©ije  §.  p.  1|ai  pbrarg 


^ortlj  (Untolina  ^Me  College 

H5 


^*^ 


l»llm.^,?,lV«s/Ty  , 


S00566496   - 


15240 

This  book  may  be  kept  out  TWO  WEEKS 
ONLY,    and    is    subject    to    a    fine    of    HPPB" 
CENTS   a   day  thereafter.   It  is   due   on  the 
day  indicated  below:  m  ^^p 


\ 


THE  PRACTICE  OF 
SILVICULTURE 

WITH  PARTICULAR  REFERENCE  TO  ITS 
APPLICATION  IN  THE   UNITED    STATES 


BY 

RALPH   C.   HAWLEY 

Professor  of  Forestry,  Yale  University 


NEW  YORK 

JOHN  WILEY  &  SONS,  Inc. 

London:  CHAPMAN  &  HALL,  Limited 
1921 


Copyright,  1921, 

BY 

RALPH  C.  HAWT^EY 


TECHNICAL  COMPOSITION  CO. 
CAMBRIDGE,    MASS.,    U.  S.  A. 


LIBRARY 

/v.  C.  state  College 


PREFACE 

The  "Practice  of  Silviculture"  has  been  prepared  for  use 
as  a  text  book  to  cover  a  field  at  present  unfilled.  So  far  as 
is  known  there  is  no  recent  book  applicable  to  the  forests  of 
this  continent  covering  the  field  of  silviculture.  Graves' 
"Principles  of  Handling  Woodlands,"  published  in  1911,  and 
Schlich's  "  Manual  of  Forestry,"  Vols.  I  and  II,  revised  in 
1895  are  practically  the  only  works  on  the  subject  in  the 
English  language.  Government  and  state  publications  con- 
tain, in  more  or  less  fragmentary  form,  a  large  store  of 
knowledge  concerning  the  practice  of  silviculture. 

Forest  Terminology  in  the  Appendix  is  copied  verbatim 
from  the  Journal  of  Forestry,  Vol.  XV,  191 7,  published  by  the 
Society  of  American  Foresters. 

The  author  does  not  claim  originality  for  the  greater  part 
of  the  information.  Available  sources  have  been  investi- 
gated and  a  selection  and  compilation  made  of  such  informa- 
tion as  is  deemed  most  useful  to-day. 

Presentation  of  the  subject  is  from  the  standpoint  of  the 
teacher  and  the  arrangement  and  discussion  are  shaped  in  a 
manner  which  it  is  beheved  will  be  clear  to  the  student. 

A  possible  criticism  in  connection  with  some  parts  of  the 
book  is  that  the  treatment  of  the  subject  is  too  theoretical. 
In  answer  to  this  it  may  be  said  that  the  writer  realizes,  from 
fifteen  years'  experience  in  applying  silviculture  on  forest 
properties  and  in  teaching  the  subject,  that,  while,  in  the 
application  of  silviculture,  methods  as  given  in  books  often 
must  be  so  modified  and  changed  to  fit  local  conditions  as  to 
.  iii 


IV  PREFACE 

be  scarcely  recognizable,  yet,  for  best  results  in  teaching 
students,  definite  theories  and  methods  must  be  elaborated 
and  set  off  distinctly  one  from  the  other. 

No  attempt  has  been  made  to  cover  in  an  absolutely  com- 
plete way  and  with  full  detail  all  branches  of  applied  silvi- 
culture. Such  a  work  can  well  be  postponed  another  decade 
until  American  silviculture  progresses  further  through  the 
formative  period.  On  the  contrary  the  purpose  has  been  to 
keep  the  text  brief  with  the  idea  of  producing  a  work  to  fill 
an  immediate  need,  containing  such  information  as  appears 
applicable  to-day  or  likely  to  be  applicable  (at  least  in  some 
parts  of  the  country)  in  the  near  future. 

The  lists  of  references  following  each  chapter  are  not  ex- 
haustive but  are  intended  to  afford  additional  reading  supple- 
menting the  text. 


CONTENTS 

PAGE 

Preface iii 

Chapter  I.    General  Considerations i 

Introductory i 

Production  in  Managed  and  Unmanaged  Forests 3 

The  Purpose  of  Silviculture 5 

The  Field  of  Silviculture 5 

The  Cost  of  Silviculture 7 

References 10 

Chapter  II.  Reproduction  Methods.  Treatment  of  the  Stand 
During  the  Period  of  Regeneration  or  Establish- 
ment   II 

Definition 11 

Standard  Reproduction  Methods 11 

Field  Identification  of  Reproduction  Methods 12 

Classification  of  Reproduction  Methods 14 

Importance  of  the  Standard  Reproduction  Methods 15 

Factors  Influencing  Natural  Reproduction 17 

Artificial  Reproduction  Compared  with  Natural  Reproduction 18 

Advantages  of  Artificial  Reproduction 19 

Advantages  of  Natural  Reproduction 21 

Opportunities  for  Applying  Artificial  Reproduction 22 

References 23 

Chapter  III.    Clearcutting  Method 25 

Definition 25 

Form  of  Forest  Produced 25 

Details  of  the  Method 25 

Clearcutting  with  Artificial  Reproduction 25 

Clearcutting  with  Natural  Reproduction 26 

Modifications  of  the  Method 32 

Clearcuttmg  in  Strips 32 

A .  Alternate  Strips 32 

B.  Progressive  Strips 32 

Clearcutting  in  Patches 37 


VI  CONTENTS 


Advantages  and  Disadvantages  of  the  Clearcutting  Method 40 

Advantages .q 

Disadvantages .q 

Application  of  the  Clearcutting  Method 41 

References .  ^ 

Ch.\pter  IV.    The  Seed  Tree  Method 44 

Definition 44 

Form  of  Forest  Produced .r 

Details  of  the  Method 4^ 

Modifications  of  the  Method r^ 

Group  Seed  Tree  Method ro 

Reserve  Seed  Tree  Method C2 

Fire  Seed  Trees 54 

Advantages  and  Disadvantages  of  the  Seed  Tree  Method 55 

Advantages r  r 

Disadvantages 55 

Apphcation  of  the  Method 57 

References ^8 


Chapter  V.    The  Shelterwood  Method. 
Definition 


Form  of  Forest  Produced 59 

DetaQs  of  the  Method 59 

Preparatory  Cuttings 59 

Seed  Cuttings 63 

Removal  Cuttings 64 

Modifications  of  the  Method 66 

Strip  Shelterwood  Method 68 

Wagner's  " Border  Cuttings" 70 

Group  Shelterwood  Method 70 

Extensive  versus  Intensive  Application 72 

Advantages  and  Disadvantages  of  the  Method 77 

Advantages 77 

Disadvantages 78 

Application  of  the  Shelterwood  Method 79 

References 81 

Chapter  VI.    The  Selection  Method 83 

Definition 83 

Form  of  Forest  Produced 83 

Details  of  the  Method 84 


CONTENTS  Vll 

PAGE 

Modifications  of  the  Selection  Method 96 

Group  Selection 96 

Strip  Selection 98 

Extensive  versus  Intensive  AppHcation  of  the  Selection  Method .  .  98 

Advantages  and  Disadvantages  of  the  Selection  Method 102 

Advantages 102 

Disadvantages 104 

Application  of  the  Selection  Method 106 

References 109 

Chapter  VII.    The  Coppice  Method iii 

Definition m 

Form  of  Forest  Produced m 

Details  of  the  Method m 

Modifications  of  the  Method 117 

The  Polewood  Coppice  Method 117 

Pollarding 119 

Advantages  and  Disadvantages  of  the  Method 121 

Advantages 121 

Disadvantages 122 

Application  of  the  Method 1 23 

References 1 25 

Chapter  VIII.    The  Coppice  with  Standards  Method 127 

Definition 127 

Form  of  Forest  Produced 127 

Details  of  the  Method 127 

Modifications  of  the  Method 136 

Advantages  and  Disadvantages  of  the  Method 136 

Advantages 136 

Disadvantages 137 

Application  of  the  Method 13S 

Conversion  of  Coppice  and  Coppice  with  Standards  into  High  Forest  139 

References 140 

Chapter  IX.    Intermediate  Cuttings , 141 

Definition  and  General  Considerations 141 

Classification  of  Intermediate  Cuttings 142 

Application  in  Evenaged  versus  Unevenaged  Stands 143 

Cleanings 144 

Liberation  Cuttings 149 

References 152 


Viii  CONTENTS 

PAGE 

Chapter  X.  ^Intermediate  Cuttings  (Contd.)  —  Thinnings 153 

Natural  Development  of  the  Stand 153 

Classification  into  Crown  Classes 154 

Advantages  of  Thinnings 156 

Time  to  Start  Thinnings 159 

Methods  of  Making  Thinnings 160 

The  German  or  Ordinar>'  ISIethod  of  Thinning 162 

Interlucation  or  Accretion  Cuttings 171 

The  French  Method 172 

Borggreve's  Method 177 

Special  Methods  of  Thinning 183 

Application  of  Thinnings 185 

References 189 

Chapter  XL    Intermediate  Cuttings  (Contd.) 192 

Improvement  Cuttings 192 

Salvage  Cuttings 194 

Severance  Cuttings 196 

Pruning 198 

References 203 

Chapter  XII.    Methods  of  Controlling  Cuttings 204 

Control  through  Inspection 204 

Control  through  Marking  of  the  Trees 205 

Marking  Rules 208 

Control  of  Waste  and  Destruction  in  Logging 211 

References 213 

Chapter  XIII.    Slash  Disposal 215 

Definition 215 

Silvicultural  Effects  of  Slash 215 

Slash  in  Relation  to  the  Soil 216 

Slash  in  Relation  to  Reproduction 217 

Slash  in  Relation  to  Forest  Fires 217 

Slash  in  Relation  to  Insects 219 

Slash  in  Relation  to  Fungi 219 

Slash  in  Relation  to  Forest  .(Esthetics 219 

Methods  of  Slash  Disposal 220 

Disposal  of  Slash  by  Pihng 220 

Disposal  of  Slash  by  Pihng  and  Burning 221 

Disposal  of  Slash  by  Burning  as  the  Logging  Proceeds 223 

Disposal  of  Slash  by  Broadcast  Burning 223 


CONTENTS  IX 

PAGE 

Disposal  of  Slash  by  Lopping 225 

Disposal  of  Slash  by  Pulling  the  Tops 226 

Light  Burning 227 

Application  of  Slash  Disposal  Methods  Under  Various  Kinds  of  Cut- 
tings   229 

Reproduction  Cuttings 229 

Cuttings  Under  the  Clearcutting  Method 229 

Cuttings  Under  the  Seed  Tree  Method 230 

Cuttings  Under  the  Shelterwood  Method 230 

Cuttings  Under  the  Selection  Method 230 

Cuttings  Under  the  Coppice  Methods 231 

Intermediate  Cuttings 231 

Selecting  the  Method  of  Slash  Disposal ■ 232 

References 235 

Chapter  XIV.  Forest  Protection 237 

General  Considerations 237 

References 240 

Chapter  XV.    Protection  Against  Forest  Fires 241 

Effects  of  Forest  Fires 241 

Annual  Fire  Loss 241 

Classification  of  the  Injuries  Caused  by  Forest  Fires 243 

Injury  to  Trees  Containing  Merchantable  Material 244 

Injury  to  Young  Growth  Including  Reproduction 246 

Injury  to  the  Soil 247 

Injury  to  the  Productive  Power  of  the  Forest 248 

Injury  to  Forage 249 

Injury  to  Stream  Flow  and  Industry 249 

Injury  to  Other  Property 250 

Injury  to  Human  Life 250 

Character  of  Forest  Fires 250 

Factors  Influencing  the  Spread  and  Severity  of  Forest  Fires 254 

Inflammable  Material 255 

Topography 257 

Atmospheric  Conditions 258 

Methods  of  Forest  Fire  Protection 259 

References 261 

Chapter  XVI.    Protection  Against  Insects 263 

Extent  of  the  Damage  Caused  by  Insects 263 

Character  of  the  Injury 263 


X  CONTENTS 

PAGE 

Insects  Responsible  for  the  Damage 265 

The  Causes  of  Insect  Attacks 265 

Methods  of  Control  and  Prevention 267 

Protection  and  Increase  of  the  Natural  Enemies  of  the  Injurious 

Insects 267 

Disposal  of  Slash  and  Other  Material  in  which  Insects  find  Favor- 
able Conditions  for  Breeding 268 

Special  Silvicultural  JMeasures  to  Prevent  the  Creation  of  Condi- 
tions Favorable  to  Injurious  Insects 270 

References .  271 

Chapter  XVII.    Protection  Against  Tree  Diseases 274 

Fungi 274 

Extent  and  Character  of  the  Injury 275 

Methods  of  Control  and  Prevention 277 

Tree  Diseases  and  Injuries  Other  than  Those  Produced  by  Fungi.  .  .  279 

References ' 280 

Chapter  XVIII.    Protection  Against  Domestic  Animals;  Grazing  284 

Introductory 284 

The  Effects  of  Grazing 285 

Effect  Upon  the  Soil 285 

Effect  Upon  Reproduction 286 

Effect  Upon  Trees  Past  the  Reproduction  Stage 287 

Effect  Upon  the  Control  and  Prevention  of  Forest  Fires 287 

Benefits  versus  Injuries  from  Grazing 287 

Methods  of  Control  and  Prevention 2S8 

Protection  by  Excluding  Domestic  Animals 289 

Protection  by  Close  Regulation  of  the  Grazing 289 

References 291 

Chapter  XIX.    Protection  Against  Animals  —  Other  than  Insects 

AND  Domestic  Animals 293 

Deer 293 

Beaver 293 

Porcupines 293 

Rabbits 294 

Squirrels 294 

Mice 294 

Birds 294 

References 295 


CONTENTS  XI 

PAGE 

Chapter  XX.    Protection  Against  Avalanches,  Landslides,  Floods 

AND  Shifting  Sand 296 

Avalanches 296 

Landslides 297 

Floods 297 

Shifting  Sands 298 

References 298 

Appendix.    Forest  Terminology 299 


THE 
PRACTICE    OF    SILVICULTURE 


CHAPTER  I 
GENERAL   CONSIDERATIONS 

Introductory.  —  B.  E.  Fernow  ^  the  Dean  of  American 
forestry  aptly  says,  "  silviculture,  the  production  of  wood 
crops,  is  the  pivot  of  the  whole  forestry  business." 

Silviculture  is  defined  as  "  the  art  of  producing  and  tend- 
ing a  forest;  the  application  of  the  knowledge  of  silvics  in 
the  treatment  of  a  forest."  *  This  definition  indicates  the 
relation  existing  between  silviculture  and  silvics.  The  latter 
deals  with  the  underlying  principles  which  control  the  life  of 
individual  forest  trees  and  stands.  It  furnishes  the  scientific 
basis  upon  which  silviculture  rests.  In  a  broader  interpre- 
tation of  the  term  silviculture  includes  the  foundations  of 
silviculture;  namely,  silvics,  the  science,  and  the  practice  of 
silviculture  or  the  art. 

An  understanding  of  silvics  is  a  pre-requisite  for  the  study 
of  silviculture  or  for  its  intelligent  appHcation.  Such  knowl- 
edge is  taken  for  granted  in  those  who  read  this  book,  which 
does  not  include  the  subject  of  silvics  within  its  scope. 

Relatively  little  is  known  concerning  silviculture.  This 
may  be  attributed  to  three  causes: 

*  Forest  Terminology.  See  Appendix.  This  is  a  compilation  of  Terms  in 
Forestry  arranged  by  a  committee  of  the  Society  of  American  Foresters.  The 
definitions  which  it  contains  will  be  used  frequently  and  accepted  as  standard 
except  as  otherwise  specified. 

I 


ntorEmr  mnART 


2  GENERAL   CONSIDERATIONS 

First,  silviculture  as  yet  has  been  practiced  to  a  limited 
extent  and  during  a  period  of  only  a  few  years  in  North 
America,  whereas  it  requires  several  decades  to  build  up 
definite  silvicultural  practice. 

Second,  silvicultural  practice  is  essentially  a  local  consider- 
ation, varying  in  important  details  from  forest  to  forest. 
Generalizations  and  the  intelligent  use  of  knowledge  gained 
by  others  develop  slowly  under  such  a  condition. 

Third,  application  of  knowledge  to  treatment  of  a  forest  is 
seriously  hampered  when  such  knowledge  is  fragmentary. 
Silvics,  which  in  theory  affords  the  scientific  basis  for  silvi- 
culture, is  still  in  its  infancy  so  far  as  furnishing  definite 
information  for  use  of  practitioners  on  numerous  important 
problems  is  concerned. 

Despite  these  difficulties  and  deficiencies  a  body  of  in- 
formation has  been  built  up  as  to  methods  and  lines  of  pro- 
cedure from  which,  as  the  starting  point,  the  details  of  local 
silviculture  must  be  worked  out. 

The  need  to-day  for  silviculture  in  practice  is  colossal  and 
coextensive  with  the  area  of  non-agricultural  land.  Business 
conditions  control  the  practice  of  silviculture  as  in  a  similar 
way  they  do  the  practice  of  agricultural  science  on  farm  lands. 
Intensive  silviculture,  like  intensive  agriculture,  pays  only, 
where  markets  for  products  are  accessible  and  prices  high. 
A  crude  application  of  silviculture  is  practicable  to-day  on  a 
great  majority  of  the  forest  lands. 

Silviculture,  like  agriculture,  requires  expenditure  or  in- 
vestment made  in  order  to  secure  some  crop  or  return  of 
more  value  than  would  be  obtained  without  such  action. 
The  return  in  agriculture  comes  within  one  year  or  at  most 
within  a  few  years  after  the  expenditure  is  made,  while  in  the 
practice  of  silviculture  the  return  is  delayed  several  decades. 
In  either  case  the  intensity  of  the  work  and  th'e  amount  of 


PRODUCTION   IN   MANAGED   AND    UNMANAGED    FORESTS         3 

the  expenditure  justified  is  in  proportion  to  the  return  to  be 
realized. 

The  long  interval  before  the  crop  can  be  harvested  is  an 
undoubted  drawback,  but  in  spite  of  this,  expenditures  in 
silvicultural  and  agricultural  practice  to  increase  productivity 
have  a  common  economic  basis.  Indeed,  when  once  ade- 
quately organized,  forest  properties  producing  timber  crops 
may  frequently  pay  as  well  as  or  better  than  lands  producing 
agricultural  crops. 

The  unmanaged  or  mismanaged  forests,  like  poorly  cared 
for  farm  lands,  do  not  produce  forest  products  of  the  kind,  in 
the  amount,  or  of  the  value  which  might  be  grown.  Silvi- 
culture, by  properly  tending  the  wild  forest  and  estabhshing 
new  forests  on  open  areas,  increases  productivity. 

Production  in  Managed  and  Unmanaged  Forests.  —  The 
unmanaged  or  mismanaged  forest  shows  lower  production 
than  it  should,  due  to  one  or  more  of  the  following 
defects. 

(a)  Species  of  quality  inferior  to  those  which  might  be 
growing  occupy  part  or  all  of  the  area.  Such  species  are  the 
weeds  of  the  silviculturist.  They  flourish  at  the  expense  of 
better  varieties.  Inferior  species  are  particularly  apt  to 
appear  after  disturbance  in  the  forest  cover,  due  to  such 
agencies  as  lumbering  and  fires.  Silviculture  must  eliminate 
and  keep  inferior  species  from  reappearing.  ''Inferior,"  as 
here  used,  is  a  relative  term,  since  a  species  may  be,  under 
one  set  of  circumstances,  the  best  tree  to  grow  and  elsewhere 
a  forest  weed. 

(b)  The  forest  may  be  too  sparsely  or  too  densely  stocked 
with  trees  for  the  best  results.  Either  of  these  two  extremes 
is  detrimental,  both  having  the  final  effect  of  reducing  the 
value  of  the  crop  produced.  Too  sparse  stocking  results  in 
part  of  the  area  being  unproductive  during  a  portion,  at  least, 


4  GENER.\L  CONSIDERATIONS 

of  the  life  cycle  of  the  forest,  while  too  dense  stocking  leads, 
as  in  the  case  of  a  thick  bed  of  beets  (to  draw  an  illustration 
from  the  garden),  to  stagnation  and  a  small  final  crop. 

Silviculture  must  provide  and  maintain  throughout  life 
enough  trees  to  properly  stock  the  area  and  no  more. 

(c)  Part  of  the  area  which  should  be  forested  is  without 
forest.  Fires,  logging  and  clearing,  for  agricultural  use,  lands 
which  are  unsuited  for  that  purpose  are  chiefly  responsible. 

The  deforested  condition  may  be  only  temporary  —  nat- 
ural seeding  stocking  the  open  lands  —  or  may  be,  for  all 
intents  and  purposes,  permanent,  due  to  the  extent  of  the 
deforested  lands  and  lack  of  trees  to  reseed  them.  Silvi- 
culture must  prevent  the  creation  of  further  open  areas  and 
restock  those  now  existing. 

(d)  Crooked,  misshapen  and  defective  trees  (even  though 
of  valuable  species)  are  apt  to  accumulate  in  the  forest  not 
under  silvicultural  treatment  and  retard  the  development  of 
better  individuals.     These  trees  should  be  removed. 

(e)  Losses,  due  to  agencies  such  as  insects,  animals,  fungi, 
wind,  etc.,  are  sustained,  often  without  salvage  of  the  dam- 
aged material  and  without  efforts  to  check  the  injury  from 
being  spread  to  adjacent  parts  of  the  forest.  Silviculture 
must  afford  protection  to  the  forest. 

(/)  Due  to  mismanagement  and  lack  of  protection  the 
forest  may  cease  to  properly  protect  the  site  on  which  it 
grows  and  lands  adjacent  to  or  indirectly  related  to  the  forest. 
The  forest  floor  may  be  destroyed  and  the  soil  eroded  or 
baked  and  cracked  open  to  the  detriment  of  the  physical 
factors  of  the  site.  Lands  depending  upon  the  forest  for 
protection  may  be  eroded  or  covered  with  infertile  soil  and 
debris.  Navigation  on  the  lower  reaches  of  streams  rising  in 
the  forest  may  be  interfered  with,  reservoirs  be  filled  and  irri- 
gation works  rendered  useless. 


THE  FIELD   OF   SILVICULTURE  5 

Silviculture  must  prevent  injuries  to  the  site  and  also  to 
lands  and  industries  dependent  upon  the  forest  for  protection. 

(g)  As  a  result  of  the  various  defects  already  mentioned  the 
production,  quantitatively,  quahtatively  and  financially,  of 
forest  products  figured  on  an  acreage  and  a  time  basis  is 
less  than  it  might  be. 

The  Purpose  of  Silviculture.  —  The  purpose  of  silviculture 
might  then  be  summed  up  as  the  creation  and  maintenance 
of  such  a  forest  as  will  yield  the  highest  returns  in  a  given 
time.  Such  a  statement  should  be  qualified,  because  the 
object  which  the  owner  of  a  forest  has  in  view  will  be  the 
controlling  factor  in  the  silvicultural  work.  The  statement 
should  be  modified  to  read:  The  purpose  of  silviculture  is 
the  production  and  maintenance  of  such  a  forest  as  shall  best 
fulfill  the  objects  of  the  owner.  Where  the  forest  must  be 
handled  with  the  object  of  furnishing  protection  to  other 
property,  silviculture  not  entirely  in  harmony  with  the  own- 
er's desires  may  have  to  be  applied,  but  this  is  an  exceptional 
case.  The  objects  of  the  owner  may  be  of  diverse  character. 
The  essential  thing  is  that  the  object  for  which  silviculture 
is  applied  be  known  and  the  treatment  be  shaped  to  the 
accomphshment  of  the  desired  end. 

The  commonest  object  for  which  silviculture  is  practiced 
is  the  production  of  the  highest  returns,  financially,  in  a  given 
time.  Protection  of  watersheds  and  lands  adjacent  to  the 
forest  and  development  of  the  best  aesthetic  effects  are  other 
objects  which  may  be  of  primary  importance  with  certain 
owners. 

The  Field  of  Silviculture.  —  The  field  of  silviculture  divides 
logically  into  three  parts  defined  as: 

I .  Treatment  of  the  stand  during  the  period  of  regeneration 
or  estabhshment :  a  consideration  of  reproduction  methods. 

When  a  bare  area  is  restocked  with  trees,  either  brought  in 


6  GENERAL  CONSIDERATIONS 

by  artificial  means  or  originating  from  natural  reproduction, 
there  ensues  a  term  of  several  years  during  which  the  young 
plants  are  being  established  or  adjusting  themselves  to  the 
new  environment.  When  this  adjustment  is  successful  and 
the  reproduction  completed  the  period  of  establishment  or 
regeneration  may  be  considered  closed. 

In  every  stand  the  time  com_es,  sooner  or  later,  when  it  is 
desired  to  harvest  a  portion  or  all  of  the  timber  and  replace 
the  trees  removed  by  others  of  a  new  generation.  Cuttings 
are  made  with  the  two  purposes  of  removing  the  old  trees 
and  establishing  reproduction.  They  are  known  as  repro- 
duction cuttings  and  the  period  over  which  they  extend  is 
known  as  the  regeneration  or  reproduction  period.  Repro- 
duction cuttings  range  from  one  to  several  in  number  and  the 
regeneration  period  may  extend  from  less  than  five  to  more 
than  50  years.  In  the  case  of  the  selection  forest  this  period 
is  identical  with  the  rotation. 

2.  Treatment  of  the  stand  during  that  portion  of  the  rota- 
tion not  included  in  the  period  of  regeneration:  a  consid- 
eration of  intermediate  cuttings. 

After  a  new  stand  is  established  on  open  land  or  on  wooded 
areas  as  a  result  of  reproduction  cuttings,  a  long  period  en- 
sues during  which  the  young  stand  grows  and  passes  through 
various  stages  until  mature  and  ready,  in  its  turn,  to  be  har- 
vested and  give  place  to  a  succeeding  generation.  The  vari- 
ous cuttings  made  during  its  development  from  the  repro- 
duction stage  to  maturity  are  termed  Intermediate  cuttings. 
They  have  as  their  object  the  improvement  of  the  existing 
stand  without  thought  of  reproduction.     (See  Fig.  i.) 

3.  Protection  of  the  stand  against  injuries  of  many  kinds. 
The  more  important  are  fire,  insects,  fungi,  animals  and  wind. 
This  subject  leads  into  various  specialized  fields,  such  as  fire 
protection,  entomology,  pathology  and  zoology. 


THE   COST   OF   SILVICULTURE 


All  of  these,  while  directly  affecting  the  production  of  tree 
crops,  usually  are  studied  as  units  by  themselves  and  will 
here  be  given  only  brief  consideration. 


Period  of 
Regeneration  or 
Establishment 

Period  of 

Regeneration  or 
Establishment 

The! 
Tree  (:rop 

1 

Period  of  Intermediate 
Cuttings 

^^             The  Tree  Crop      j 

Period  of  Intermediate 
Cuttings 

^^       Tree  Crop 

0   3        10 
50  54     60  years 


Preceding ->  < — 
Rotation 


Present  Rotation 


60  years 

0   3       10  20  30  years 

■  -* — Succeeding  Rotation 


Fig.  I. 

An  illustration  based  on  eastern  white  pine  managed  on  a  6o  year  rotation 
under  shelterwood  to  show  the  relation  between  the  period  of  regeneration  and 
the  period  of  intermediate  cuttings. 

The  Cost  of  Silviculture.  —  The  production  of  tree  crops, 
in  common  with  other  commercial  enterprises,  involves  the 
assumption  of  certain  investments  and  expenditures.  Com- 
pared with  the  business  of  harvesting  standing  forest  products 
{i.e.,  logging),  the  costs  will  be  greater  for  silviculture,  since 
the  former  simply  conducts  the  first  stages  of  utilization  or 
manufacture  of  any  existing  crop  of  trees  and  does  not  have 
as  its  function  the  growing  of  succeeding  crops. 

A  common  way  of  expressing  the  costs  of  silviculture  is  to 
compare  them  with  the  costs  of  the  business  of  logging,  thus 
indicating  the  extra  expenditures  and  investments  required. 

The  question  of  whether  silviculture  is  "  impracticable " 
(a  term  too  often  loosely  employed  in  this  connection)  does 


8  GENER.\L   CONSIDERATIONS 

not  depend  upon  the  relative  costs  of  the  two  distinct  busi- 
nesses —  viz.,  logging  timber  and  growing  tiniber  —  but,  in 
reahty,  hinges  upon  whether  a  profit  ultimately  can  be  made  in 
excess  of  the  expenditures  necessary  in  growing  the  tree  crop. 

It  is  true  that  the  lack  of  capital  to  invest  and  of  the  finan- 
cial strength  to  carry  an  investment  for  a  period  of  years  bar 
many  owners  of  forest  property  from  practicing  silviculture. 

Where  the  desire  to  enter  the  business  of  forestry  exists  in 
conjunction  with  the  requisite  amount  of  capital,  silviculture 
will,  in  the  majority  of  cases,  prove  to  be  a  practical  under- 
taking. Forest  properties  sufficiently  well  stocked  with  tim- 
ber to  return  an  immediate  and  continuous  income  offer  more 
favorable  opportunities  for  the  practice  of  silviculture  than 
those  upon  which  the  timber  is  so  deficient  as  to  necessitate  a 
long  period  of  waiting  before  returns  on  the  investment  are 
available. 

The  actual  costs  of  silviculture  and  the  degree  to  which 
they  increase  the  cost  of  logging  are  subject  to  wide  varia- 
tion. Graves^  stated  in  191 1  that  the  cost  of  silviculture, 
expressed  in  terms  of  the  annual  cut,  is  likely  to  fall  between 
50  cents  and  $1.00  per  thousand  feet,  board  measure.  In 
calculating  the  extra  cost  of  logging  timber  on  the  National 
Forests,  as  contrasted  with  the  unrestricted  logging  on  private 
lands,  for  California  forests  in  1918  Birch  ^  concludes  that 
expenditures  are  increased  $0,855  P^^  thousand  feet,  board 
measure,  and  lowered  $0.78,  making  the  net  excess  of  cost 
$0,075  per  thousand  feet,  board  measure.  In  favorable  in- 
stances a  crude  application  of  silviculture  may  involve  very 
shght  increased  charges.  On  the  other  hand  intensive  appli- 
cation may  require  large  initial  costs,  although  eventually 
returning  better  net  profits  than  the  crude  application. 

It  is  not  purposed  to  attempt  a  statement  of  the  actual 
costs,  but  rather  to  set  forth  the  various  classes  of  items 


THE   COST  OF   SILVICULTURE  .  9 

which  must  be  considered  in  determining  the  cost  of  silvi- 
culture in  the  case  of  an  individual  property.  These  items 
are  arranged  under  the  following  five  major  headings. 

1.  Cost  of  Reproduction.  The  artificial  regeneration  of  the 
area  by  seeding  or  planting  may  be  required.  Treatment  of 
the  soil,  litter,  ground  cover  or  underbrush  may  be  needed 
to  establish  proper  seedbed  conditions  for  natural  reproduc- 
tion. It  may  be  necessary  to  retain  a  portion  of  the  old 
stand,  either  for  a  part  or  for  all  of  the  next  rotation,  to  provide 
seed  or  the  right  amount  of  shelter.  The  young  seedlings, 
naturally  or  artificially  started,  may  require  cleanings  to 
secure  their  final  establishment. 

2.  Cost  of  Protection.  Annual,  periodic  or  special  expendi- 
tures are  likely  to  be  necessary  against  one  or  more  enemies. 
Examples  are :  the  annual  charges  for  the  prevention  of  forest 
fires;  the  periodic  eradication  of  ribes  species  in  the  eastern 
white  pine  regions;  and  special  work  on  cutting  areas  to  dis- 
pose of  brush,  trees  affected  with  fungi  or  insects  and  snags, 
and  for  fighting  fires  or  dangerous  outbreaks  by  other  ene- 
mies. The  cost  of  insurance  (where  such  can  be  economi- 
cally secured),  or  the  carrying  and  distribution  of  a  certain 
fixed  charge  per  acre  to  cover  average  losses  from  enemies,  is 
a  proper  charge  against  silviculture. 

3.  Increased  Expenses  of  Logging.  Increased  costs  of  log- 
ging come  principally  through  the  need  of  greater  care  in 
felling,  bucking  and  skidding,  to  save  young  growth  and  seed 
trees  left  on  the  cutting  area,  and  in  the  heightened  costs  per 
thousand  feet,  board  measure,  of  construction  work,  due  to 
a  decreased  cut  when  part  of  the  merchantable  stand  is  left. 
The  leaving  of  the  smaller  trees  may  effect  a  saving  in  logging 
costs,  because  such  trees  are  the  most  expensive  to  handle  and 
produce  the  lowest  quality  of  product.  Disposal  of  the  slash 
may  so  clear  the  area  as  to  effect  a  reduction  in  skidding  costs. 


lO  GENERAL  CONSIDERATIONS 

.  4.  Cost  of  Administration.  The  marking  of  the  trees  to  be 
cut  or  left,  extra  inspection  and  supervision,  to  see  that  cutting 
and  other  work  is  carefully  and  properly  executed,  are  likely 
to  be  necessary. 

5.  Costs  Due  to  Making  the  Investment  a  Permanent  One. 
The  investment  in  the  value  of  the  land  may  become  per- 
manent instead  of  being  terminated,  through  sale  or  devotion 
to  other  use,  when  the  area  is  cut  over. 

A  considerable  investment  in  wood  capital  (the  growing 
stock)  is  required  where  silviculture  is  systematically  applied. 
Interest  and  taxes  upon  the  investment  in  land  and  wood 
capital  must  be  met. 

REFERENCES 

1.  Fernow,  B.  E.  Suggestions  as  to  Possibilities  of  Silviculture  in  America. 
Proceedings  of  the  Society  of  American  Foresters,  Vol.  XI,  1916,  pp.  171-176. 

2.  Graves,  H.  S.  Principles  of  Handling  Woodlands.  New  York,  191 1, 
p.  19. 

3.  Birch,  D.  C.  Extra  Costs  of  Logging  National  Forest  Stumpage. 
Journal  of  Forestry,  Vol.  XVI,  1918,  pp.  909-914. 

Chxjrchill,  H.  L.  The  Approximate  Cost  of  Private  Forestry  Measures  in 
the  Adirondacks.     Journal  of  Forestry,  Vol.  XVIII,  1920,  pp.  26-30. 

Graves,  H.  S.  Present  Condition  of  American  Silviculture.  Proceedings  of 
the  Society  of  American  Foresters,  Vol.  Ill,  1908,  pp.  29-40. 

WoOLSEY,  T.  S.  Jr.  Studies  in  French  Forestry.  Wiley  &  Sons,  Inc.,  New 
York,  1920.  (This  excellent  book,  pubHshed  Dec.  1920,  arrived  too  late 
to  be  referred  to  in  detail.  The  best  that  can  be  done  is  to  list  it  here 
as  a  valuable  reference  book  on  various  phases  of  Sihnculture,  —  particu- 
larly Chapters  v  and  vi.) 


CHAPTER  II 

REPRODUCTION   METHODS 

Treatment  of  the  Stand  during  the   Period  of  Regeneration 
or  Establishment 

Definition.  —  A  reproduction  method  may  be  defined  as  an 
orderly  procedure  or  process  by  which  a  forest  is  renewed  or 
estabHshed  either  naturally  or  artificially.  This  process  is 
accomplished  during  the  reproduction  or  regeneration  period, 
which  comes  when  the  stand  is  harvested  at  the  end  of  every 
rotation.  It  is  accomplished  through  skillful  cuttings  of  the 
mature  timber  supplemented  where  necessary  by  special 
treatment  to  create  and  maintain  conditions  favorable  for  the 
start  and  early  life  of  reproduction.  Where  artificial  meth- 
ods of  regeneration  are  employed,  as  may  be  the  case  in  re- 
newing established  forests  and  must  be  used  in  reforesting 
open  lands,  the  seeding  or  planting  of  the  area  is  included  as 
part  of  the  process. 

The  term  "  silvicultural  system"  is  used  frequently  as  prac- 
tically S3nionymous  with  reproduction  method.  As  some- 
times employed  it  is  intended  to  include  both  the  reproduction 
method  and  the  intermediate  cuttings  applied  in  a  given  case. 

Standard  Reproduction  Methods.  —  Many  different  repro- 
duction methods  have  been  developed,  but  they  can  be  re- 
duced on  analysis  to  a  few  standard  methods  which  are 
applicable  in  principle  the  world  round.  In  practice  the 
details  of  applying  a  standard  reproduction  method  may  vary 
for  every  species,  forest  region  and  owner.     As  time   passes 


12  REPRODUCTION  METHODS 

this  leads  to  the  origin  of  quite  definite  reproduction  methods 
worked  out  in  detail  and  based  on  local  practice  which  may 
be  advanced  as  original  and  advocated  for  general  adoption. 
Under  close  examination  such  methods  prove  to  be  mere 
modifications  of  the  few  standard  reproduction  methods  and 
not  as  applicable  for  general  use  as  the  standard  methods. 

Combinations  of  several  reproduction  methods  within  the 
same  stand  are  common  practice  in  treating  the  irregular 
unmanaged  forests  which  are  the  rule  to-day  Eventually 
only  one  method  will  be  applied  within  a  single  stand  be- 
cause each  method  produces  distinctive  results  and  recog- 
nizable differences  in  the  character  of  the  forest,  which  make 
it  advisable  to  have  stand  boundaries  coincide  with  variations 
in  reproduction  methods. 

Field  Identification  of  Reproduction  Methods.  —  Since 
local  adaptations  of  reproduction  methods  are  developed 
wherever  silvicultural  practice  is  applied,  difficulty  frequently 
is  experienced  in  determining  under  what  standard  method  a 
given  series  of  reproduction  cuttings  should  be  classed. 

Identification  in  the  forest  of  the  reproduction  methods  is 
particularly  puzzling  in  a  country  where  all  forestry  practice 
has  taken  place  within  the  last  twenty  years  and  most  of  it 
within  the  last  ten.  A  field  inspection  of  the  cuttings  to- 
gether with  information  about  the  matters  listed  below  should 
make  possible  a  correct  decision  as  to  the  reproduction  method. 
Information  should  be  obtained  as  to: 

(a)  The  form  of  forest  which  will  be  produced  under  the 
method  of  cutting  in  operation.  Certain  reproduction  meth- 
ods result  in  the  maintenance  of  even-aged  stands;  others 
produce  irregular  or  uneven-aged  stands. 

(b)  Character  of  the  present  cutting.  There  are  such  ob- 
vious differences  in  character  of  the  reproduction  cuttings 
between  many  of  the  methods  that  a  field  inspection  sheds 


FIELD   IDENTIFICATION   OF   REPRODUCTION   METHODS      13 

much   light   on   the   method.     On   the   other  hand   certain 
methods  are  quite  ahke  in  their  first  reproduction  cutting. 

(c)  Length  of  time  which  will  elapse  before  the  next  re- 
production cutting  and  what  the  character  of  that  cutting 
will  be. 

(d)  The  length  of  the  rotation  and  length  of  the  reproduc- 
tion period.  The  length  of  the  rotation  determines  the  allow- 
able range  in  age  between  individual  trees  if  that  particular 
stand  is  to  be  classed  as  even-aged.  The  longer  the  rotation 
the  greater  can  be  the  difference  in  age  between  individual 
trees  without  loss  of  the  even-aged  form.  For  instance  if  the 
rotation  is  50  years,  a  difference  in  age  of  10  years  might  be 
the  maximum  and  have  the  stand  still  remain  even-aged,  while 
if  the  rotation  were  200  years,  differences  of  40  to  50  years 
between  individuals  would  be  allowable. 

(e)  Origin  of  the  reproduction,  whether  from  sprout  or 
seed,  whether  naturally  or  artificially  obtained. 

(/)  The  minimum  size  of  area  considered  as  a  subdivision 
in  the  forest.  In  other  words  the  minimum  size  of  the  indi- 
vidual stand  or  portion  of  the  forest  differing  from  adjacent 
portions  in  composition,  character  or  age.  Such  minimum 
size  will  be  determined  principally  by  the  intensity  of  the 
silvicultural  operations  which  in  turn  is  controlled  by  the 
economic  situation.  Where  intensive  work  is  possible,  areas 
of  less  than  one  acre  may  be  recognized  as  subdivisions.  (See 
Fig.  2.)  If  work  on  an  extensive  scale  alone  is  possible  it 
may  be  that  subdivisions  of  less  than  several  hundred  acres  are 
impracticable.  The  minimum  size  of  the  single  stand  or  sub- 
division is  important  in  its  effect  on  the  form  of  the  stand. 
Large  areas  of  forest  are  much  less  uniform  in  composition, 
character  or  age  than  small  areas  which  may  be  separated  out 
from  within  a  single  large  area.  For  example  a  forest  of  1000 
acres  located  in  the  southern  Appalachian  mountains  distant 


14 


REPRODUCTION  METHODS 


from  markets  may  be  handled  as  a  single  stand  of  irregular 
age.  The  same  forest  if  located  within  five  miles  of  a  large 
city  may  be  divided  into  twenty  to  one  hundred  different  sub- 
divisions or  stands  most  of  which  are  classed  as  even-aged. 

The  same  cutting  which  in  the  first  instance  has  to  be 
classed  as  selection  may  in  the  second  furnish  examples  of 
clearcutting  and  shelterwood  methods. 


Fig.  2. 

Map  of  portion  of  forest  property  showing  the  division  into  subcompart- 
ments  (stands)  based  on  type  distinctions  and  (within  the  same  tj^ie)  upon 
lo  year  age  class  differences.  The  upper  figures  are  the  sub-compartment 
numbers,  while  those  below  the  type  name  indicate  the  age  class. 

Due  consideration  of  all  these  factors  in  their  relations 
with  one  another  should  be  given  in  analyzing  a  reproduction 
method  in  its  application  in  the  forest. 

Classification  of  Reproduction  Methods.  —  The  classification 
of  reproduction  methods  which  will  be  used  agrees  in  all 
but  one  particular  with  that  given  in  Forest  Terminology.* 

*  The  difference  comes  in  including  under  the  clearcutting  method,  repro- 
duction both  artificially  and  naturally  secured,  which  are  listed  as  two  separate 
methods  under  Forest  Terminology,  in  Journal  of  Forestry,  Vol.  XV,  p.  89. 


IMPORTANCE   OF   STANDARD   METHODS  15 

Standard  Reproduction  Methods 

High  Forest  Methods:  —  Producing  forests  originating  from 
seed. 

Clearcutting  method. 
•    Seed  tree  method. 
Shelterwood  method. 
Selection  method. 

Coppice  Forest  Methods:  —  Producing  forests  originating 
wholly  or  mainly  from  sprouts  and  suckers. 

Coppice  method. 

Coppice  with  standards  method. 

Each  of  these  methods  is  treated  in  a  separate  chapter  to 
which  reference  should  be  made  for  definitions  and  discussion. 

Importance  of  the  Standard  Reproduction  Methods.  — 
There  is  a  tendency  in  some  quarters  to  belittle  the  import- 
ance of  recognizing  standard  reproduction  methods.  This 
may  be  attributed  to  several  causes. 

First,  because  of  a  tendency  to  undervalue  methods  of 
European  origin.  These  standard  methods  arose  in  Euro- 
pean practice  and  find  there  to-day  their  most  elaborate  de- 
velopment. It  is  what  logically  is  to  be  expected  since  for- 
estry was  first  practiced  abroad.  Despite  the  great  difference 
in  economic  conditions  between  Europe  and  America  the 
laws  of  growth  of  trees  and  stands  are  the  same.  The  stand- 
ard reproduction  methods  have  a  sound  basis  in  silvics  which 
will  hold  on  both  continents. 

Second,  because  of  failure  to  recognize  that  any  one  of 
these  standard  methods  is  to  be  applied  only  as  a  framework, 
allowing  wide  range  in  respect  to  details  to  fit  the  purely  local 
needs  of  each  forest. 

Natural  reproduction  follows  cuttings  not  as  a  direct  result 


l6  "        REPRODUCTION  METHODS 

of  the  cuttings  themselves,  but  due  to  favorable  site  condi- 
tions. Theoretically  these  conditions  should  be  created  by 
the  cuttings.  A  reproduction  method  is  successful  in  so  far 
as  it  accomplishes  this  and  the  variation  in  detail  of  appli- 
cation is  for  the  purpose  of  creating  the  proper  site  conditions. 

As  the  standard  reproduction  methods  are  studied  it  be- 
comes apparent  that  one  method  grades  into  another  and  that 
into  still  another  and  so  on  in  a  complete  series  embracing  all 
the  possible  ways  of  removing  a  mature  stand  by  cutting. 
In  passing  through  this  series  every  conceivable  combination 
of  open  and  dense  stands,  of  young  and  old  trees,  with  the 
consequent  maximum  range  in  desired  effect  upon  basic  site 
factors  possible  to  produce  by  cuttings  can  be  obtained. 

Just  as  the  sites  in  a  given  region  range  in  a  continuous 
series  from  the  least  to  the  most  productive  but  are  separ- 
ated arbitrarily  into  a  few  broad  classes  for  use,  so  with 
reproduction  methods  the  gradations,  from  one  method 
through  various  modifications  to  another,  are  almost  un- 
noticed, when  taken  step  by  step,  yet  show  extremes  at  the 
limits  of  the  series  and  are  for  puq^oses  of  practical  use 
classed  into  a  few  main  divisions.  Any  possible  combina- 
tion of  cuttings  for  harvesting  a  merchantable  crop  of  timber 
and  replacing  it  by  a  new  stand  can  be  placed  under  one  of 
the  six  standard  reproduction  methods. 

Third,  because  in  the  irregular  overmature  virgin  forest 
now  being  cut  in  parts  of  this  country,  the  style  of  cutting 
is  rather  rigidly  circumscribed  by  the  condition  of  the  timber, 
logging  possibilities  and  other  economic  conditions  and  con- 
sists in  removing  all  or  a  very  large  proportion  of  the  mer- 
chantable timber  without  thought  of  any  particular  repro- 
duction method.^ 

Such  reproduction  as  follows  the  cutting  comes  haphazard 
and  uncontrolled,  but  will  receive  protection.     Such  forests 


FACTORS   INFLUENCING   NATURAL  REPRODUCTION       1 7 

are  in  the  transition  stage  between  the  unmanaged  forest 
of  the  past  and  the  managed  forest  of  the  future.  After  the 
first  cutting  which  utilizes  the  old  overmature  trees  the  possi- 
bilities and  necessity  of  cutting  systematically  to  secure  re- 
production will  be  seen. 

Factors  Influencing  Natural  Reproduction.  —  The  method 
of  cutting  is  only  one  among  a  number  of  factors  which  con- 
trol the  establishment  of  natural  reproduction,  such  as  cli- 
matic conditions  (which  is  the  dominating  factor),  occurrence 
of  seed  years,  grazing  and  other  injuries  by  animals,  insects, 
fungi  and  fire.  All  these  factors,  outside  of  what  direct 
mechanical  influence  some  of  them  may  exert  in  destroying 
established  reproduction,  affect  the  start  and  early  develop- 
ment of  reproduction  through  influence  upon  such  funda- 
mental factors  as  temperature,  moisture  and  light  which  are 
of  direct  controlling  importance.  For  successful  natural  re- 
production there  must  be: 

(i)  Abundant  seed  supply  in  excess  of  that  destroyed  by 
rodents,  insects  and  other  agencies ; 

(2)  Favorable  conditions  for  germination  of  seed; 

(3)  Favorable  conditions  for  the  growth  of  seedlings. 

Each  species  is  likely  to  have  different  requirements  and 
will  vary  more  or  less  in  its  own  requirements  in  different 
parts  of  its  range.  The  silviculturist  should  be  equipped 
with  a  definite  knowledge  of  the  basic  requirements  for  nat- 
ural reproduction  of  the  species  with  which  he  deals,  and 
should  also  know  the  effect  in  establishing  and  maintaining 
these  requirements  which  methods  of  cutting,  fire,  grazing, 
etc.,  possess.  Supplied  with  this  knowledge  he  can  utilize 
cuttings,  fire  and  other  means,  so  far  as  control  of  them  may 
be  in  his  power,  to  establish  and  maintain  the  conditions 
requisite  for  reproduction. 


l8  REPRODUCTION  METHODS 

A  reproduction  method  then  has  for  its  object  the  estab- 
lishment of  reproduction  and  the  removal  of  the  old  crop. 
Its  first  purpose  may  possibly,  though  rarely  be  achieved  as  a 
direct  result  of  the  cuttings.  More  probably  the  method  of 
cutting  is  only  one  of  a  number  of  factors  some  within  the 
control,  some  without  the  control  of  the  silviculturist,  but 
each  exerting  their  effect  on  environmental  conditions. 

A  reproduction  method  will  include  more  than  the  making 
of  cuttings.  Other  work  to  insure  reproduction  may  have 
to  be  pursued.  For  example,  the  use  of  fire,  protective 
methods  against  insects  and  animals,  cultural  operations  to 
prepare  the  soil,  conserve  moisture  and  to  lessen  the  compe- 
tition with  grass,  herbs  and  shrubs,  the  use  or  exclusion  of 
grazing,  and  disposal  of  slash  as  well  as  other  matters  may 
any  one  or  all  have  a  vital  connection  with  the  securing  of  a 
complete  reproduction. 

Unfortunately  the  science  of  silvics  has  not  yet  supplied  either 
the  accurate  detailed  knowledge  of  the  silvical  requirements  of 
most  commercial  species  nor  has  it  determined  with  precision 
the  exact  effects  of  the  various  factors,  cutting,  fire,  grazing, 
etc.,  upon  the  moisture,  light  and  heat  conditions  of  the  site. 

Meanwhile  the  silviculturist  must  advance  as  he  can,  often 
making  mistakes,  because  he  acts  on  information  resting  too 
largely  on  an  empirical  basis.  It  is  the  ignorance  and  back- 
wardness of  silvics  the  science  which  forces  silviculture  to 
grope  in  the  dark  as  it  carries  on  the  art. 

Artificial  Reproduction  Compared  with  Natural  Reproduc- 
tion. —  Establishment  or  renewal  of  a  forest  may  be  obtained 
by  (a)  seed,  (6)  sprouts,  from  the  stump,  or  from  the  roots 
(root  suckers),  (c)  cuttings  and  (d)  layering.  In  the  practice 
of  silviculture,  layering  is  not  employed,  cuttings  are  used 
infrequently  and  dependence  is  placed  upon  seed  or  sprouts 
to  insure  reproduction. 


ARTIFICIAL  REPRODUCTION  19 

Reproduction  may  be  accomplished  by  either  natural  or 
artificial  means.  Natural  reproduction  accomplishes  its 
purpose  by  self-sown  seeds  or  by  sprouts  and,  in  instances  so 
rare  as  to  have  no  commercial  importance,  by  layering.  Arti- 
ficial reproduction,  defined  as  the  renewal  of  a  forest  by  direct 
seeding  or  planting,  utilizes  either  seeds  or  young  plants 
grown  from  seeds  or  cuttings. 

Of  these  two  methods  natural  reproduction  is  the  more  im- 
portant because  of  the  fact  that  it  will  be  used  on  all  but  a 
small  proportion  of  the  forest  area. 

Artificial  reproduction  while  logically  a  part  of  and  in- 
cluded under  reproduction  methods  is  more  conveniently 
treated  as  a  unit  by  itself.  This  is  due  to  the  fact  that  two 
subjects,  namely,  the  collection  and  treatment  of  tree  seeds 
and  the  growing  in  nurseries  of  trees  for  planting  must  be 
developed  to  considerable  length  in  connection  with  the  estab- 
lishment of  forests  by  artificial  means. 

The  comparative  advantages  of  natural  and  artificial  re- 
production are  outlined  in  the  succeeding  pages  and  later 
under  each  reproduction  method  is  indicated  the  extent  to 
which  artificial  reproduction  may  be  employed. 

For  a  detailed  discussion  of  the  various  ways  of  securing 
reproduction  by  artificial  means  the  reader  is  referred  to 
special  works  on  artificial  reproduction,  particularly  to  "Seed- 
ing and  Planting  in  the  Practice  of  Forestry,"  by  J.  W. 
Toumey.^ 

Both  artificial  and  natural  reproduction  have  special  ad- 
vantages of  their  own  which  are  best  considered  in  a  com- 
parative way.  Among  those  in  favor  of  artificial  reproduc- 
tion are  the  following: 

Advantages  of  Artificial  Reproduction.  —  i.  The  new  stand 
can  be  established  immediately  without  the  loss  of  time  which 
occurs  when  dependence  is  placed  on  natural  reproduction. 


20  REPRODUCTION  METHODS 

It  may  take  from  ten  to  thirty  years  after  the  cutting  for  an 
area  to  completely  restock  by  natural  means.  Very  rarely  can 
natural  reproduction  be  accomphshed  immediately  after  a  cut- 
ting. On  short  rotations  this  advantage  may  be  of  great  finan- 
cial importance. 

2.  The  species  best  adapted  to  fulfilling  the  purposes  of 
the  owner  can  be  grown.  Frequently  the  trees  which  repro- 
duce naturally  on  a  given  area  are  of  inferior  value  and  rate 
of  growth  to  other  varieties  which  could  be  produced.  Arti- 
ficial reproduction  makes  it  possible  to  introduce  new  and 
better  species. 

3.  Complete  reproduction  is  more  certain  under  artificial 
methods  than  when  naturally  obtained.  Not  only  is  time  lia- 
ble to  be  wasted  in  securing  natural  reproduction  but  it  may 
even  happen  that  the  latter  is  a  partial  or  entire  failure.  In 
many  instances  natural  reproduction  may  come  in  large 
enough  quantities  to  stock  the  area  but  proves  to  be  of  the 
wrong  species.  Natural  reproduction  in  mixed  stands  espe- 
cially is  difficult  to  predict  in  advance  because  of  this  factor. 

4.  The  right  spacing  is  secured  to  produce  the  desired 
results.  Natural  reproduction  is  apt  to  be  either. too  sparse 
or  too  dense.  The  number  of  trees  per  acre  established 
artificially  is  calculated  so  as  to  fulfill  the  objects  of  the  owner. 

5.  Artificial  reproduction  permits  the  employment  of  a 
relatively  simple  reproduction  method  when  more  compli- 
cated and  hence  expensive  methods  may  be  required  to  secure 
reproduction  naturally. 

6.  The  yield  per  acre  in  quantity  and  value  should  average 
higher  than  in  naturally  reproduced  stands  due  principally  to 
the  saving  in  time  of  estabHshment,  the  use  of  the  best  spe- 
cies and  the  right  spacing.  There  undoubtedly  are  many 
naturally  reproduced  stands  which  have  these  three  requisites 
that  yield  as  much  as  or  more  than  those  artificially  reproduced. 


ARTIFICIAL   REPRODUCTION  21 

7.  In  the  case  of  over-mature  stands  of  old  growth  timber, 
reproduction  by  artificial  means  may  be  the  only  available 
method,  due  to  the  valuable  species  in  such  stands  having 
ceased  the  production  of  seed.  This  situation  will  be  an  ex- 
ceptional case  rather  than  one  of  every  day  occurrence. 

A  dvantages  of  Natural  Reproduction.  —  i .  Natural  reproduc- 
tion is  Nature's  method  and  should  renew  the  forest  with  spe- 
cies adapted  to  the  site.  It  is  apt  to  produce  a  mixed  forest 
which  is  considered  less  susceptible  to  injuries  and  more  pro- 
ductive than  a  pure  forest,  which  is  the  usual  kind  produced 
by  artificial  means.'*  While  the  above  may  be  true  in  the 
forest  undisturbed  by  other  than  natural  factors  it  does  not 
follow  that  it  will  hold  in  the  forest  after  cuttings.  Should  the 
forest  contain  only  valuable  species  and  the  cuttings  not  create 
conditions  unfavorable  for  their  reproduction  then  Nature's 
method  may  prove  successful.  On  the  other  hand,  it  is  quite 
possible  that  an  inferior  species  in  pure  stands  may  be  the 
result  secured. 

As  a  consequence  of  artificial  reproduction  injuries  by  in- 
sects and  certain  other  agencies  such  as  snow  breakage,  and 
windfall,  are  unquestionably  more  extensive  than  in  the  mixed 
naturally  reproduced  stand. 

On  the  whole  the  argument  that  natural  reproduction  is 
Nature's  method  is  not  a  particularly  strong  one  when  com- 
paring with  artificial  reproduction. 

2.  Natural  reproduction  as  compared  with  artificial  repro- 
duction is  better  suited  to  the  less  intensive  methods  of  silvi- 
culture which  must  be  employed  for  many  years  over  the  larger 
share  of  the  forest  area.  To  regenerate  existing  forests  by 
artificial  methods  requires  work  of  intensive  character  which 
the  country  is  not  ready  for  on  a  big  scale. 

3.  Natural  reproduction  is  cheaper  on  the  whole  than 
artificial  reproduction.     On  many  forest  areas  natural  repro- 


22  REPRODUCTION  METHODS 

duction  can  be  secured  for  practically  nothing  or  at  a  fraction 
of  the  expenditure  required  to  reforest  artiticially.  The  re- 
production so  obtained  and  the  stand  finally  produced  may 
not  compare  with  that  possible  under  artificial  methods, 
although  the  question  is  often  an  open  one  as  to  whether  the 
poor  naturally  reproduced  stand  may  not  exceed  in  final  net 
value  the  better  artificial  one. 

There  are  many  cases  where  natural  reproduction  does  not 
cost  more  than  artificial  reproduction.  Stumpage  values  of 
the  trees  left  to  establish  reproduction  may  be  a  loss,  and  log- 
ging costs  per  thousand  feet  board  measure  due  to  the  smaller 
amount  cut  per  acre  may  be  increased. 

Even  though  the  greater  net  returns  of  artificially  repro- 
duced stands  may  be  quite  clearly  demonstrable,  the  actual 
amount  of  the  initial  cash  expenditure  may  make  the  propo- 
sition impracticable  for  the  owner. 

4.  Natural  reproduction  must  be  employed  on  many  areas 
because  of  the  physical  limitations  in  the  way  of  applying 
artificial  reproduction. 

Artificial  reforestation  on  a  large  scale  requires  ^  (a)  col- 
lection and  cleaning  of  large  quantities  of  seed,  (b)  produc- 
tion of  immense  quantities  of  young  trees,  (c)  organization  of 
big  squads  of  laborers  and  usually  the  planting  of  extensive 
areas  back  from  transportation  lines  and  centers  of  popula- 
tion. The  work  must  be  accomplished  in  the  short  period  of 
a  few  weeks  in  each  year  when  climatic  conditions  permit  of 
seeding  or  planting. 

In  theory  this  program  may  appear  simple  but  in  execution 
has  never  yet  in  North  America,  even  by  state  or  federal 
agencies,  been  conducted  on  a  scale  adequate  to  the 
needs. 

Opportunities  for  Applying  Artificial  Reproduction.  —  In 
general  the  field  for  artificial  reproduction  to-day  is  in  refor- 


REFERENCES  23 

esting  burns  and  other  areas  which  are  at  present  non-for- 
ested, and  which  are  either  so  far  distant  from  seed  trees  or 
suffer  such  unfavorable  site  conditions  as  to  preclude  the 
possibility  of  natural  restocking. 

The  vast  extent  of  barren  areas  due  to  clearcuttings  and 
fires,  together  with  other  open  lands,  will  require  many  dec- 
ades to  reforest  and  will  tax  the  capacity  of  all  agencies  to 
supply  necessary  seeds,  plants,  labor  and  funds.  These  lands 
are  now  unproductive.  Artificial  reproduction  should  be 
largely  confined  for  the  next  half  century  at  least  to  reforest- 
ing this  type  of  land.  Only  in  the  regions  where  intensive 
management  is  possible,  and  in  which  the  proportion  of  open 
unproductive  land  is  small  should  artificial  reproduction  of 
existing  forests  be  undertaken.  Here  the  funds  for  relatively 
large  initial  outlay  often  are  av  ailable  and  the  size  of  the  pro- 
jects are  within  the  range  of  present  physical  limitations. 

Artificial  methods  of  reproduction  are  most  commonly  ap- 
plied when  using  the  clearcutting  method  or  in  reforesting 
open  land.  There  is  a  field  and  a  distinct  need  for  artificial 
regeneration  under  other  reproduction  methods  intensively 
applied  to  supplement  natural  reproduction  by  stocking  the 
blanks. 

REFERENCES 

1.  Clapp,  E.  H.  Silvicultural  Systems  for  Western  Yellow  Pine.  Proceed- 
ings of  the  Society  of  American  Foresters,  Vol.  7,  191 2,  p.  169. 

2.  TouMEY,  J.  W.  Seeding  and  Planting  in  the  Practice  of  Forestry. 
Wiley  &  Sons,  Inc.,  New  York,  1916. 

3.  MuNGER,  T.  T.  Natural  versus  Artificial  Regeneration  in.  the  Douglas 
Fir  Region  of  the  Pacific  Coast.  Proceedings  of  the  Society  of  American 
Foresters,  Vol.  VII,  191 2,  pp.  187-196. 

4.  NiSBET,  J.     Studies  in  Forestry.     Oxford,  1894,  pp.  1 15-137 

ReusS;  Hermann.     Die  Forstliche  Bestandesbegriinding.     Berlin,    1907,  pp. 
1-38. 


nOPERTY  JWRARY 
JV.  C.  State  College 

24  REPRODUCTION  METHODS 

Secrest,  E.  The  Role  of  Artificial  Regeneration  in  the  Re-enforcement  of 
Hardwood  Woodlots.     Journal  of  Forestrj^,  Vol.  XVI,  1918,  pp.  329-334. 

TiLLOTSON,  C.  R.  Forest  Planting  in  the  Eastern  United  States.  Bulletin 
153,  U.  S.  Department  of  Agriculture,  Washington,  1915. 

Troup,  R.  S.  A  note  on  some  European  Sj'lvicultural  Systems,  with  Sug- 
gestions for  Improvement  in  Indian  Forest  Management.     Calcutta,  1916. 


CHAPTER  m 
THE   CLEARCUTTING   METHOD 

Definition.  —  In  the  clearcutting  method  the  area  is  cut 
clear.  Reproduction  is  secured  after  the  cutting  either  arti- 
ficially by  seeding  or  planting,  or  naturally  by  seed  distributed 
from  trees  standing  outside  the  area  cleared  or  from  trees  cut 
in  the  clearing  operation.  Depending  on  how  reproduction 
is  secured  the  method  divides  into  (i)  clearcutting  with 
artificial  reproduction  and  (2)  clearcutting  with  natural 
reproduction. 

Form  of  Forest  Produced.  —  A  clearcutting  operation  as 
a  practical  method  can  be  used  only  in  a  stand  where  the 
trees  are  all  of  merchantable  size.  Such  a  stand  may  be 
either  evenaged  or  contain  several  age  classes  the  youngest  of 
which  contains  trees  as  large  as  or  larger  than  the  minimum 
merchantable  size.  The  new  stand  originating  on  a  clear 
cut  area  is  evenaged  irrespective  of  whether  the  timber  before 
the  cutting  was  irregular  or  evenaged  in  character.  In  almost 
all  stands  of  merchantable  timber  no  matter  how  evenaged  in 
form  there  will  be  occasional  small  unmerchantable  trees 
which  remain  standing  after  a  clearcutting.  The  majority 
of  such  trees  are  soon  windthrown  or  die  as  a  result  of  the 
changed  conditions  following  the  cutting. 

Details  of  the  Method.  —  The  two  different  ways  of  secur- 
ing reproduction  each  require  separate  consideration  in  dis- 
cussing the  details  of  the  clearcutting  method. 

Clearcutting  with  Artificial  Reproduction.  —  In  this  simple 
method  the  stand  is  cut  clear  and  reproduced  by  seeding  or 
25 


26  THE   CLEARCUTTING  ]\IETHOD 

planting.*  Usually  the  artificial  regeneration  is  accomplished 
soon  after  the  clearcutting.  The  cleared  area  is  likely  to 
become  stocked  with  grass,  weeds,  underbrush  or  undesirable 
trees  which  may  prevent  or  render  expensive  the  process  of 
artificial  reproduction.  In  exceptional  cases  it  may  be  of  ad- 
vantage to  defer  seeding  or  planting  for  one  or  more  years. 
For  example,  this  may  be  advisable  when  it  is  desired  to  allow 
time  for  a  thick  humus  to  decompose,  or  when  injuries  to  the 
new  stand  by  insects  breeding  in  stumps  or  tops  can  be  avoided 
by  delay. 

Lumber,  logs  and  cordwood  should  be  removed  from  the 
area  before  it  is  regenerated  in  order  to  prevent  damage  to 
the  young  plants. 

A  clearcutting  results  in  a  large  accumulation  of  tree  tops 
and  other  logging  debris.  This  may  be  so  abundant  as  to 
interfere  mechanically  with  the  seeding  or  planting  operations 
or  constitute  a  serious  fire  hazard.  If  so  this  material  should 
either  be  piled  and  burned  or  burned  broadcast.  See  chapter 
relating  to  Slash  Disposal. 

Heavy  underbrush  may  have  to  be  disposed  of  in  a  similar 
manner. 

As  the  young  reproduction  develops  it  will  on  many  sites 
be  overtopped  by  inferior  trees  and  other  vegetation.  The 
proper  treatment  of  the  young  stand  under  such  circum- 
stances is  discussed  in  Chapter  IX  under  Cleanings  and  Liber- 
ation Cuttings. 

Clearcutting  with  Natural  Reproduction.  —  The  stand  is  cut 
clear  and  reproduction  springs  up  naturally  on  the  clear  area. 
This  reproduction  to  secure  best  results  should  start  imme- 
diately but  frequently  requires  several  years.  The  seed  from 
which  the  new  stand  originates  comes  from  three  sources: 

*  For  discussion  of  the  details  of  seeding  and  planting  see  "Seeding  and 
Planting  in  the  Practice  of  Forestry,"  by  J.  W.  Tourney. 


DETAILS   OF  THE  METHOD  2^ 

(a)  Trees  standing  outside  (usually  adjacent  to)  the  area 
cleared.  The  seed  is  disseminated  (by  wind)  over  the  cleared 
area  most  thickly  close  to  the  parent  trees  on  the  borders  of 
the  clearing  and  in  decreasing  amount  toward  the  center. 
Reproduction  arising  from  such  seeding  is  apt  to  be  too  dense 
around  the  edges  and  too  sparse  or  lacking  altogether  in  the 
middle.     (See  Fig.  3.) 

(b)  Seed  stored  in  the  duff.  With  some  species  under  cer- 
tain climatic  conditions  quantities  of  seed  may  accumulate  in 
the  forest  floor  retaining  vitahty  for  many  years  and  germi- 


Voung  Timber 


Fig.  3- 
Clearcutting  the  whole  stand,  with  reproduction  secured  by  seed  disseminated 
from  seed  trees  located  outside  the  stand  cut.     The  density  of  the  reproduction 
five  years  after  the  cutting  is  indicated  by  the  dots. 

nating  when  subjected  to  the  changed  conditions  following  a 
clearcutting.^  Reproduction  secured  in  this  way  may  be 
relatively  uniform  in  its  distribution  over  large  areas. 

(c)  Seed  stored  on  the  trees  removed  in  the  clearcutting,  or 
recently  fallen  from  these  trees.  Certain  species  (lodgepole 
pine  for  example  ^)  retain  portions  of  several  seed  crops  for 


28  THE   CLEARCUTTIXG  IMETHOD 

a  number  of  years.  Following  cutting  (also  after  fires)  such 
seed  may  be  released  and  germinate.  With  most  species  the 
seed  stored  on  the  trees  is  the  current  seed  crop.  This  may 
be  still  on  the  trees  or  recently  fallen  to  the  ground.  A  uni- 
form and  complete  reproduction  will  frequently  follow  where 
this  source  of  seed  is  available  on  the  cleared  area. 

Successful  natural  reproduction  following  a  clearcutting 
depends  first  on  an  abundant  seed  supply  over  the  entire 
area  and  second  upon  the  existence  of  conditions  favorable  to 
the  germination  of  the  seed  and  development  of  the  young 
seedlings. 

Since  clearcutting  differs  more  from  Nature's  system  of 
regeneration  than  do  other  reproduction  methods,  it  follows 
that  the  two  requirements  for  success  of  the  method  must  be 
met  with  precision  before  natural  reproduction  will  appear. 

In  providing  for  an  abundant  seed  supply  the  sources  from 
which  seed  may  be  expected  and  the  probable  amount  must  be 
considered,  as  well  as  the  natural  enemies,  especially  rodents, 
which  may  destroy  the  seed.  In  artificial  seeding  it  is  often 
necessary  to  distribute  poison  systematically  over  the  area 
to  be  reproduced  in  order  to  kill  the  rodents.  Such  methods 
applied  just  before  a  seed  year  in  stands  about  to  be  repro- 
duced naturally  might  be  effective  in  increasing  the  seed 
supply  available  for  germination.  No  instances  are  kno-\vn 
where  this  has  been  done  the  expense  being  large  and  the 
uncertainty  great  as  to  whether  this  step  would  guarantee 
natural  reproduction.  Where  seed  from  surrounding  trees  is 
the  only  source  the  clearing  must  be  sufficiently  small  (usu- 
ally long  and  narrow)  to  allow  for  adequate  dissemination 
to  all  points.  Direction  of  the  wind  at  the  time  of  seed  dis- 
persal should  be  known  and  the  clearing  so  located  that  its 
long  axis  is  at  right  angles  to  the  wind  direction. 

Unless  the  cleared  area  can  be  made  very  narrow  a  heavy 


DETAILS   OF  THE  METHOD  29 

seeded  species,  depending  principally  upon  gravity  for  dis- 
semination, will  not  furnish  sufficient  seed  from  trees  outside 
the  clearing.  When  seed  in  the  duff  or  on  the  trees  which 
are  to  be  cut  is  available  the  weight  of  the  seed  becomes 
less  important. 

After  providing  for  an  adequate  dispersal  of  seed  over  the 
clearing,  favorable  conditions  for  germination  and  early 
growth  of  seedlings  of  the  desired  species  must  be  established 
and  maintained  for  a  few  years.  Estabhshment  and  main- 
tenance of  such  conditions  in  many  cases  will  require  special 
work  undertaken  for  this  specific  purpose. 

The  silvical  habits  of  the  species  together  with  the  condi- 
tion of  the  site  will  indicate  the  character  and  amount  of  the 
work  needed.  In  general  such  treatment  falls  under  one  of 
three  heads : 

(a)  Disposal  of  the  slash  left  by  the  lumbermen. 

A  variety  of  methods  to  accomplish  this  is  available. 
(See  Chapter  XIII.)  As  already  stated  piling  and  burning  or 
else  broadcast  burning  are  commonly  used  on  clearings.  The 
brush  may  be  silviculturally  of  advantage  in  conserving  moist- 
ure and  protecting  seedlings  and  in  some  cases  may  properly 
be  left  untouched. 

(b)  Removal  of  weeds,  vines,  shrubs  and  reproduction  of 
undesired  species  which  threaten  to  prevent  germination  or 
growth  of  seedlings.^'  ^  A  fire  running  over  the  whole  area  in 
the  latter  part  of  the  summer  is  the  cheapest  and  most  effec- 
tive remedy  for  destroying  the  undesirable  vegetation  which 
may  be  present  before  reproduction  starts. 

Such  burning  may  bring  in  a  different  kind  of  reproduction 
from  that  sought.  If  this  is  likely  cutting  or  grubbing  out 
of  the  objectionable  vegetation  may  be  necessary.  This  will 
be  more  expensive  than  the  use  of  fire.  Where  the  shrubs  and 
reproduction  of  undesired  species  are  too  large  to  be  cheaply 


30  THE   CLEARCUTTING  METHOD 

cut  and  disposed  of,  girdling  may  be  employed.  From  the 
standing  trees  the  bark  is  removed  in  a  ring  around  the  trunk 
and  if  necessary  to  cause  death,  a  groove  is  chopped  in 
through  the  sapwood. 

A  cover  may  be  of  benefit  to  young  seedlings  in  protecting 
them  from  frost,  heat  or  wind.  In  such  cases  the  cover 
should  be  preserved  so  long  as  it  serves  a  useful  purpose. 
Within  a  few  years  this  cover  ceases  to  be  of  benefit  to  the 
reproduction  and  becomes  a  hindrance  to  its  proper  develop- 
ment. Cleanings  must  then  be  made  to  uncover  the  repro- 
duction and  estabhsh  it  in  a  dominant  position. 

(c)  Treatment  of  the  Soil.  Frequently  nothing  need  be  done 
to  improve  soil  conditions.  The  rate  of  decomposition  in- 
creases on  a  cleared  area  and  may  sufficiently  expose  the  soil 
and  make  available  plant  foods  without  any  special  treat- 
ment. Logging  when  there  is  no  snow  on  the  ground  often 
results  in  mixing  mineral  soil  and  duff  into  an  ideal  seedbed. 

Where  further  treatment  is  needed,  burning  over  the  area 
to  remove  the  duff  and  lay  bare  the  mineral  soil  is  sometimes 
undertaken.  Breaking  up  the  soil  in  patches  or  furrows 
with  a  plow,  log  drag,^  spade  or  other  implement  will  often 
be  effective. 

Moisture  conditions  on  the  clearing  can  be  partially  con- 
trolled by  varying  the  width  of  the  area  cut  clear.  With  a 
narrow  strip,  the  adjacent  timber  affords  protection  against 
sun  and  wind.  Proper  regulation  of  moisture  conditions  may 
make  the  difference  between  success  and  failure  of  the  repro- 
duction. 

In  both  forms  of  the  clearcutting  method  (with  artificial 
or  with  natural  reproduction)  so  far  considered  the  entire 
stand  has  been  cut  clear.  One  or  more  stands  will  make  up 
the  annual  cut  of  the  forest.  The  forest  should  contain 
enough  stands  to  permit  of  one  or  more  being  cut  each  year. 


DETAILS   OF  THE  METHOD 


31 


In  order  to  avoid  too  large  clearings  for  reasons  already  con- 
sidered or  to  be  explained  under  ''Advantages  and  Disad- 
vantages," these  stands  are  kept  relatively  small,  or  at  least 
narrow  in  one  dimension.  Stands  cut  in  consecutive  years 
should  be  scattered  throughout  the  forest  so  arranged  that 
timber  of  seedbearing  age  is  adjacent  on  one  or  more  sides 
and  that  recently  cut  over  stands  are  not  contiguous.  (See 
Fig.  4-) 


2 

1 
1 
1 
1 
_1 

53 

1 

40 

39 

16 

r 

1 

.8  i 

10 

1 

42 

J 

31 

■"" 

1 
1 
1 
J. 

""" 

._JL. 

" 

60 

"" 

'" 

"" 

1 

1 

4 

1 
1 

24 

._i 

3 

57 

__J 

12 

1 

j 

35 

18 

59 

Fig.  4. 

Theoretical  arrangement  of  a  portion  of  the  stands  in  a  forest  managed  on  a 
60  year  rotation  and  reproduced  by  clearcutting  the  whole  stand.  The  num- 
bers indicate  the  present  age  of  each  stand.  For  example  the  stand  marked 
"12"  was  cut  over  12  years  ago  and  now  is  stocked  with  trees  12  years  of  age. 
The  one  marked  "60"  will  be  cut  clear  during  the  present  year. 


32  THE  CLEARCUTTING  METHOD 

Modifications  of  the  Method.  —  Modifications  in  applica- 
tion of  the  method,  outside  of  changes  in  details  which  are 
expected  to  vary  with  each  species  and  locality,  affect  princi- 
pally the  portion  of  the  stand  which  is  cut  clear  at  one  time. 
Under  the  ordinary  meaning  the  term  ''clearcutting"  impHes 
the  removal  of  the  whole  stand  at  one  time.  Where  the  in- 
dividual stand  is  of  large  area  it  may  take  several  years  to 
complete  the  operation. 

The  reasons  for  extending  a  clearcutting  operation  through 
more  than  one  year  arises  not  entirely  from  logging  consid- 
erations as  to  what  can  be  covered  in  a  year,  although  this 
may  have  weight.  More  important  are  the  silvical  require- 
ments of  the  species,  particularly  available  seed  supply  and 
conditions  necessary  for  germination.  These  factors  should 
determine  whether  the  whole  stand  may  be  cut  at  one  time. 

Depending  upon  whether  the  timber  is  removed  in  one  or 
more  operations,  and  upon  the  relative  size,  shape  and  loca- 
tion of  the  portions  cut  in  a  single  operation,  the  clearcutting 
methods  may  be  classified  as : 

Clearcutting  the  whole  stand 
Clearcutting  in  strips 

Alternate  strips 

Progressive  strips 
Clearcutting  in  patches. 

The  first  method  has  already  been  discussed;  it  remains  to 
consider  the  last  two. 

Clearcutting  in  Strips.  —  {A)  Alternate  Strips.  Under  this 
arrangement  the  stand  is  divided  into  a  series  of  strips  as 
shown  m  Fig.  5  and  Fig.  6.  The  first  strip  is  cut  clear,  the 
next  left  standing,  the  third  cut,  and  so  on  throughout  the 
stand.  A  few  years  later  after  reproduction  is  established,  the 
timber  on  the  uncut  strips  is  removed. 


MODIFICATIONS  OF  THE  METHOD 


33 


The  two  cuttings  must  occur  close  enough  together  in  point 
of  time  so  that  the  resultant  stand  is  evenaged.  From  one  to 
20  years  under  ordinary  circumstances  represents  the  possible 
range  of  interval  between  the  two  cuttings.  Three  to  10  years 
may  be  considered  the  average  interval. 


Fig.  5. 

Illustrates  the  arrangement  of  the  strips  in  a  stand  to  be  reproduced  by  clear- 
cutting  in  alternate  strips. 


A 

B 

A 

B 

A 

B 

A 

i 

j3 

.5? 

.a 

B 

|4.5  ft 

1 

Fig.  6. 

The  same  stand  as  shown  in  Fig.  5;  but  ten  years  after  the  clearcutting  of 
the  strips  marked  A  and  five  years  after  the  clearcutting  and  reproduction  by 
planting  of  the  strips  marked  B.  While  there  are  now  differences  in  height 
and  age  between  the  reproduction  on  the  two  sets  of  strips  yet  these  differences 
are  too  small  to  cause  the  stand  as  a  whole  to  lose  its  evenaged  form.  The 
difference  in  height  will  decrease  as  the  stand  grows  older. 

Reproduction  may  be  secured  either  artificially  or  naturally. 
In  general  clearcutting  the  whole  stand  is  used  when  arti- 
ficial reproduction  is  to  be  employed.  This  is  because  the 
need  for  providing  and  distributing  an  adequate  supply  of 


34  THE  CLEARCUTTING  INIETHOD 

seed  and  for  creating  ideal  seedbed  conditions  becomes  of 
importance  only  where  dependence  is  placed  upon  natural 
reproduction. 

The  timber  on  the  uncut  strips  furnishes  a  portion  or  all  of 
the  seed  for  stocking  the  uncut  strips,  to  some  extent  favor- 
ably affects  site  conditions  on  uncut  strips  and  affords  pro- 
tection to  the  seedlings  which  start.  To  perform  these  func- 
tions to  best  advantage  the  uncut  strips  must  be  relatively 
close  together,  and  be  located  at  right  angles  to  the  wind 
direction  at  seed  dispersal  time. 

When  the  strips  of  timber  left  at  the  time  of  the  first  cut  are 
removed,  natural  reproduction  on  these  areas  cannot  be 
secured  in  the  same  way  as  on  the  strips  first  cut.  There  are 
no  belts  of  timber  left  to  furnish  seed.  The  seed  must  come 
from  the  trees  which  are  cut  or  else  resort  must  be  had  to 
artificial  reproduction.  If  a  seed  year  can  be  selected  as  the 
time  for  making  the  second  cutting  successful  reproduction 
may  be  secured.  In  many  cases  the  cutting  cannot  be  de- 
layed until  a  good  seed  year.  Under  such  circumstances  in 
order  to  secure  natural  reproduction  some  other  method  than 
clearcutting  may  be  used  to  reproduce  the  strips  left  standing 
at  the  first  cutting.  The  seed  tree  or  the  shelterwood  meth- 
ods are  commonly  employed.  Refer  to  Chapters  IV  and  V. 
The  use  of  either  of  these  necessitates  two  or  more  cuttings 
to  remove  the  timber,  and  hence  lengthens  the  total  period  of 
regeneration.  Reproduction  may  in  some  cases  be  hastened 
and  made  more  certain  by  thinning  the  uncut  strips  at  the 
time  the  first  strips  are  clear  cut. 

The  simplest  and  most  satisfactory  way  of  reproducing  the 
strips  left  after  the  first  cutting  is  to  cut  them  clear  and  plant. 
This  combines  natural  reproduction  on  the  first  strips  with 
artificial  regeneration  upon  the  second. 

In  Fig.  5,  50  per  cent  of  the  area  has  been  assigned  to 


MODIFICATIONS  OF  THE  METHOD 


35 


strips  to  be  cut  in  the  first  operation  and  50  per  cent  left  for 
the  second  operation.  This  proportion  is  not  a  requirement 
of  the  strip  method.  (See  Fig.  7.)  From  30  to  70  per  cent 
of  the  area  might  be  cut  in  the  first  operation.  Owing  to 
the  greater  difficulties  in  securing  natural  reproduction  on  the 
strips  cut  in  the  second  operation,  60  to  70  per  cent  (roughly 
two-thirds  of  the  area)  ordinarily  should  be  cut  over  in  the 
first  operation.  By  making  the  uncut  strips  only  half  as  wide 
as  those  cut  this  proportion  is  obtained.  There  is  danger  in 
making  the  uncut  strips  too  narrow.  They  must  be  wide 
enough  to  offer  protection  to  the  cleared  area,  to  be  windfirm 


Uncut  Strip 


Uncut  Strip 


Uncut  Strip 


Strip 
cut 

Clear 
<-75ftT^ 

/^f^age'^and-'^/ 
/;;75,feet;Mgh^ 

.  \  strip 
y  ^  cut 
,  S  Clear 

vyyyyyy. 

Strip 
cut 
Clear 

^^ 

Fig.  7. 


Alternate  strip  method,  where  one-third  of  the  area  is  cut  clear  in  the  first 
cutting.  The  cut  strips  are  half  the  width  of  the  uncut  strips  and  equal  in  width 
to  the  height  of  the  timber. 

in  storms  and  be  large  enough  to  make  the  second  operation 
practicable  as  a  logging  proposition.  In  general  the  strips 
left  should  be  at  least  as  wide  as  the  height  of  the 
timber. 

Some  windfall  must  be  anticipated  along  the  edges  of  the 
cleared  area.  This  can  be  minimized  by  careful  selection  of 
the  trees  to  be  left  on  the  borders  of  the  strips.  The  strips 
cut  for  most  species  will  range  in  width  from  two  to  four 
times  the  height  of  the  stand. 

iB)  Progressive  Strips.  In  this  method  three  or  more  opera- 
tions are  required  to  remove  the  timber.  Apphed  in  its 
simplest  form  strip  cuttings  are  made  at  short  intervals 
starting  at  one  side  of  the  stand  and  advancing  progressively 
across  to  the  other  side.     (See  Fig.  8.) 


36 


THE  CLEARCUTTING  METHOD 


The  entire  series  of  cuttings  must  be  finished  within  a 
short  enough  period  (lo  to  20  years,  depending  on  length  of 
rotation),  to  make  the  new  growth  on  the  whole  area  even- 
aged  if  the  method  is  to  be  classed  as  clearcutting.  In  large 
stands  the  entire  area  could  not  be  cut  over  in  a  short  enough 
time  to  produce  evenaged  timber  and  at  the  same  time  keep 


First  clear  Cutting 


A  simple  case  of  a  small  stand  reproduced  under  the  method  of  clearcuttmg 
in  progressive  strips. 

the  individual  strip  narrow  enough  to  reproduce  success- 
fully unless  more  than  one  cutting  series  is  initiated. 

To  overcome  the  difficulty  several  strips  may  be  cut  in  one 
year,  each  in  a  separate  cutting  series  as  shown  in  Fig.  9  and 
Fig.  10.  A  large  stand  can  be  cut  clear  under  this  arrange- 
ment with  as  much  protection  to  reproduction  as  may  be 
secured  in  a  small  stand  with  a  single  cutting  series.  Repro- 
duction may  be  secured  either  artificially  or  naturally.  Where 
the  latter  method  is  used  the  uncut  portions  of  each  cutting 
series  furnish  seed  and  protection  to  seedlings.  Each  succes- 
sive cutting  should  follow  its  predecessor  as  soon  as  reproduc- 
tion is  established  on  the  last  strip  cut.  This  may  vary  from 
two  to  five  years.  If  natural  reproduction  has  not  started  in 
satisfactory  amount  at  the  end  of  five  years,  resort  should  be 
taken  to  artificial  reproduction. 


MODIFICATIONS   OF  THE  METHOD 


37 


When  the  time  comes  to  cut  the  last  strip  of  the  cutting 
series  artificial  reproduction  must  be  used  or  natural  repro- 
duction secured  by  some  other  method. 

Clearcutting  in  Patches.  —  Where  the  topography  is  rugged 
and  irregular  in  character,  where  soil  conditions  show  wide 


Cutting  Series 


Cutting  Series 


Fig.  9. 

Clearcutting  in  progressive  strips,  using  three  cutting  series.  The  last 
strip  (No.  3)  in  each  series  may  be  reproduced  by  a  method  other  than  clear- 
cutting. 

Age  of  the   Reproduction 

15  years  15  years  15  years 


//^/\  10  years 
/^"^ /  /  J.K  /  A  5  years 

y/. 

/\  10  years 

''^  >    /    /    '\  5  years 

/  /  A  10  years 

V^////Pr9^ 

'Vr/  /  /SK  /  /  /  / 

/  / 

/  /  /  /y  /  / 

Fig.  10. 

The  same  stand  as  shown  in  Fig.  9;  but  five  years  after  the  clearcutting  and 
reproduction  by  planting  of  the  strips  marked  3.  Despite  the  present  difference 
in  height  and  age  the  stand  is  evenaged. 

range  within  relatively  small  areas  and  where  the  evenaged 
stand  is  lacking  in  uniformity,  there  the  regular  arrangement 
of  cutting  areas  necessary  under  the  strip  method  is  imprac- 
ticable. 

The  patch  or  group  method,  which  is  in  reality  merely  an 
irregular  strip  method,  can  be  employed  instead. 


38  THE   CLEAR  CUTTING   I^IETHOD 

It  requires  two  or  more  operations  to  remove  the  timber  in 
a  given  stand.  In  the  first  cutting  patches  are  selected 
which  for  some  reason  should  be  cut  before  the  rest  of  the 
stand.  A  patch  of  injured  trees  or  an  opening  in  which 
seedlings  are  already   springing  up  and  which  need   more 


4*^  =  Timber  injured  by  Insects        Q=i  =  Timber  injured  by  Wind 

^it?  =  Advance  Reproduction  ''^=  Swampy  Ground  subject  to  Windfall 

Fig.  II. 

Clearcutting  in  patches.  Areas  marked  "  1 "  are  cut  clear  in  the  first  opera- 
tion. Their  location  is  based  on  the  condition  of  the  timber  as  respects  injury 
by  wind  or  insects,  presence  of  advance  growth  or  location  on  swamp)^  ground. 
In  this  illustration  26  per  cent  of  the  area  is  cleared  in  the  first  cutting. 

light  may  determine  the  location  of  the  first  cutting.  (See 
Fig.  II.)  Timber  on  swampy  ground  or  on  rocky  knolls  which 
if  left  exposed  by  adjacent  cutting  might  be  windthrown  may 


MODIFICATIONS  OF  THE   METHOD 


39 


be  included  in  the  patches  cut  in  the  first  operation.  Fre- 
quently the  shape  of  the  hills  and  direction  of  the  slopes  makes 
an  irregular  and  patchy  arrangement  of  the  cutting  areas 
advisable. 

When  the  entire  stand  is  removed  in  two  operations  the 
method  resembles  alternate  strips  in  all  details  except  the 
irregular  shape  of  the  cutting  areas.     When  more  than  two 


Same  stand  as  in  Fig.  1 1  showing  the  location  of  the  three  cutting  operations 
used  in  removing  the  timber.  The  new  stand  wiU  be  evenaged  in  spite  of  minor 
differences  in  height  and  age.  Areas  marked  "1"  are  cut  in  the  first  cutting; 
those  marked  "2"  in  the  second  and  those  marked  "3"  in  the  third. 

operations  are  required  to  remove  the  timber  it  is  similar  to 
the  progressive  strip  method  except  for  the  irregular  shape 
of  the  cutting  areas.     (See  Fig.  12.) 


40  THE   CLEARCUTTING   METHOD 

Advantages  and  Disadvantages  of  the  Clearcutting 
Method.  —  Advantages.  —  i.  Best  method  for  stands  of  over- 
mature timber  and  for  mature  timber  of  large  size.  Silvicul- 
turally  and  financially  such  stands  are  ready  for  utilization. 
It  is  usually  poor  silviculture  as  well  as  impracticable  from 
the  logging  side  to  cut  large  sized  mature  or  over-mature 
timber  otherwise  than  clear. 

2.  Logging  is  concentrated  on  relatively  small  areas.  This 
tends  to  keep  logging  and  transportation  costs  low. 

3.  Avoids  loss  of  timber  by  windfall.  Frequently  on  ex- 
posed slopes  and  ridges  and  on  shallow  soils  and  swamps 
where  poor  root  development  occurs,  clearcutting  is  the  only 
safe  method.  On  soils  which  become  saturated  with  moist- 
ure at  seasons  of  the  year  when  heavy  winds  prevail,  clear- 
cutting  should  be  practiced.  With  shallow  rooted  species  the 
necessity  for  clearcutting  is  greater  than  with  deep  rooted 
species. 

Trees  which  have  been  grown  under  conditions  of  dense 
stocking  show  poor  crown  development  and  a  correspond- 
ingly poor  root  system.  With  such  timber  clearcutting  is 
often  the  only  safe  method  of  treatment. 

4.  When  it  is  desired  to  change  the  species  to  one  not  now 
found  in  the  stand,  clearcutting  is  the  best  method.  Arti- 
ficial reproduction  is  a  requisite  in  effecting  this  change. 

5.  Furnishes  a  bare  exposed  site  for  the  start  of  natural 
reproduction.  Where  such  condition  is  demanded  by  a  given 
species  for  best  reproduction  clearcutting  should  be  employed. 

6.  Clearcutting  is  simple  and  easy  to  practice. 

7.  The  period  of  regeneration  in  each  stand  being  confined 
to  a  small  portion  of  the  rotation  permits  use  of  the  area  for 
grazing  during  the  remainder  of  the  time. 

Disadvantages.  —  i.  The  clearing  of  the  area  induces  condi- 
tions which  for  most  species  are  adverse  to  the  growth  of 


APPLICATION  OF  THE  METHOD  41 

seedlings  and  render  uncertain  establishment  of  a  satisfactory 
reproduction. 
Such  results  may  come  from : 

(a)  Deterioration  of  the  physical  factors  of  the  soil. 

(b)  Appearance  of  a  grass,  brush  and  weed  growth  which 
competes  too  successfully  with  reproduction. 

(c)  Exposure  of  reproduction  to  the  drying  influence  of  sun 
and  wind,  and  to  injury  by  frost. 

(d)  Greater  activity  of  insects  than  is  the  case  where  re- 
production is  secured  under  the  shelter  of  older  trees. 

2.  Affords  poor  protection  against  erosion,  landslides,  snow- 
slides  and  rapid  run-off  of  water.  In  its  protection  value  to 
the  site  and  indirectly  to  other  lands  the  clearcutting  method 
ranks  lowest  and  selection  highest. 

3.  ^Esthetically  is  the  least  desirable  of  the  four  high  forest 
methods. 

These  disadvantages  are  minimized  as  the  size  of  the  clear- 
ing is  reduced,  but  correspondingly  the  advantage  of  con- 
centrating logging  and  transportation  on  a  small  area  is 
lost. 

Application  of  the  Clearcutting  Method.  —  Clearcutting 
because  of  its  simplicity  and  the  high  production  of  valuable 
timber  possible  in  its  evenaged  stands  has  been  extensively 
used  in  countries  where  forestry  has  been  practiced  longest,, 
particularly  with  shallow  rooted  species  like  Norway  spruce 
and  where  reproduction  is  secured  artificially.  In  the  United 
States  clearcutting  of  extensive  areas  was  and  is  the  com- 
mon practice  of  the  lumbermen  wherever  the  character  of 
the  timber  enabled  him  to  sell  all  the  standing  trees.  Hun- 
dreds of  thousands  of  acres  have  been  left  barren  wastes 
through  a  careless  or  improper  use  of  the  method.  As  for- 
estry practice  develops  there  will  be  innumerable  opportuni- 


42  THE   CLEAR  CUTTING  METHOD 

ties  for  applying  properly  the  different  variations  of  clear- 
cutting.  Many  conifers,  such  as  Douglas  fir  and  several  of 
the  southern  pines,  can  be  reproduced  naturally  following 
clearcutting.  Cuttings  in  virgin  timber,  due  to  the  large 
size  of  maturity  of  all  individuals  must  in  many  instances, 
be  of  this  t}^^  Stands  containing  one  or  more  inferior 
species  frequently  demand  clearcutting  and  the  establish- 
ment artificially  of  a  valuable  species  to  replace  those  now 
present.  Work  along  this  line  is  of  intensive  character  and  is 
being  undertaken  to-day  principally  on  small  tracts  in  the 
north  Atlantic  states. 

Clearcutting  with  natural  reproduction  where  seed  comes 
from  trees  outside  the  area  cut  over  is  suitable  only  for  rela- 
tively few  light  demanding  and  light  seeded  species  capable 
of  starting  on  exposed  areas.  Scrub  pine  in  the  region  of 
its  best  development  on  the  Piedmont  Plateau  might  be 
successfully  reproduced  by  this  method. 

With  a  species  like  Douglas  fir  where  dependence  can  be 
placed  on  the  seed  supply  stored  in  the  forest  floor  clear- 
cutting  with  natural  reproduction  should  prove  successful. 

A  good  example  of  clearcutting  with  natural  reproduction, 
the  seed  supply  coming  largely  from  cones  stored  on  the 
trees  removed  in  the  cutting,  is  found  in  the  case  of  certain 
evenaged  overmature  lodgepole  pine  stands.^ 

When  the  clearcutting  can  be  made  immediately  following 
an  abundant  seed  year,  thus  utilizing  the  current  seed  crop 
from  the  trees  cut,  the  method  can  be  extended  in  its  appli- 
cation to  a  broader  range  of  species. 

Clearcutting  the  whole  stand  is  especially  suitable  for 
areas  to  be  reproduced  artificially  or  where  in  organized  forest 
naturally  reproduced  the  area  included  in  a  single  stand  is 
small.  The  strip  and  patch  modifications  are  useful  in 
stands  of  large  area  or  where  detailed  and  intensive  practice 


REFERENCES  43 

is  possible.    As  yet  they  have  been  used  to  only  a  small 
extent  in  this  country. 

REFERENCES 

1.  HoFMAN,  J.  V.  Natural  Reproduction  from  Seed  Stored  in  the  Forest 
Floor.     Journal  of  Agricultural  Research,  Vol.  XI,  Washington,  191 7,  pp.  1-26, 

2.  Mason,  D.  T.  Life  History  of  Lodgepole  Pine  in  Rocky  Mountains. 
Bulletin  154,  United  States  Department  of  Agriculture,  Washington,  1915, 
pp.  9-10. 

3.  Williamson,  A.  W.  Cottonwood  in  the  Mississippi  Valley.  Bulletin 
24,  United  States  Department  of  Agriculture,  Washington,  1913,  pp.  33-37. 

4.  Sterrett,  W.  D.  Forest  Management  of  Loblolly  Pine  in  Delaware, 
Maryland  and  Virginia.  Bulletin  11,  United  States  Department  of  Agricul- 
ture, Washington,  1914,  p.  33. 

5.  Pearson,  G.  A.  Management  of  Pine  and  Spruce  in  Sweden.  Review 
of  Skogsvardsforeningens  Folksrifter,  1-12,  No.  12,  "Skogens  Vard  Ock 
Afverkning,"  by  F.  Aminoff.  Proceedings  of  the  Society  of  American  For- 
esters, Vol.  9,  1914,  p.  452. 

6.  Mason,  D.  T.  Utilization  and  Management  of  Lodgepole  Pine  in  the 
Rocky  Mountains.  Bulletin  234,  United  States  Department  of  Agriculture, 
Washington,  1915,  pp.  25-26. 

Bryant,  R.  C.  Silviculture  at  Axton  and  in  the  Adirondacks  Generally. 
Journal  of  Forestry,  Vol.  15,  1917,  pp.  891-893. 

Fisher,  R.  T.,  and  Terry,  E.  I.  The  Management  of  Second  Growth  White 
Pine  in  Central  New  England.  Journal  of  Forestry,  Vol.  18,  1920,  pp. 
358-363. 

Frothingham,  E.  H.  White  Pine  under  Forest  Management.  Bulletin  13*, 
United  States  Department  of  Agriculture,  Washington,  1914,  pp.  39-41. 

Hofman,  J.  V.  The  Importance  of  Seed  Characteristics  in  the  Natural  Re- 
production of  Coniferous  Forests.  Studies  in  the  Biological  Sciences,  Num- 
ber 2.    The  University  of  Minnesota,  Minneapolis,  191 8. 

Mattoon,  W.  R.  Shortleaf  Pine:  Its  Economic  Importance  and  Forest 
Management.  Bulletin  308,  United  States  Department  of  Agriculture, 
Washington,  1915,  pp.  46-47. 

Murphy,  L.  S.  The  Red  Spruce:  Its  Growth  and  Management.  Bulletin 
544,  United  States  Department  of  Agriculture,  Washington,  191 7,  pp. 
48-51. 

Recknagel,  B.  a.  Some  Aspects  of  European  Forestry,  Forestry  Quarterly, 
Vol.  XI,  1913,  pp.  135-148. 


CHAPTER  IV 

THE   SEED   TREE   METHOD 

Definition.  —  The  area  is  cut  dear  except  for  certain  trees 
(called  seed  trees)  left  standing  singly  or  in  groups  for  the 
purpose  of  furnishing  seed  to  restock  naturally  the  cleared 
area.     Only  a  small  percentage  of  this  total  volume,  ordi- 


FlG.   13. 
A  stand  reproduced  by  the  scattered  seed  tree  method,  leaving  approximately 
one  seed  tree  per  acre  in  fairly  even  distribution. 

narily  less  than  10  per  cent,  is  left  standing  as  seed  trees. 

(See  Fig.  13.)     These  seed  trees  after  the  new  crop  is  estab- 

44 


DETAILS   OF  THE  METHOD  45 

lished  may  be  removed  in  a  second  cutting,  or  left  indefinitely. 
In  the  latter  case  they  usually  are  a  total  loss,  rarely  surviv- 
ing in  a  sound  condition  until  the  end  of  the  second  rotation. 

In  some  classifications  the  seed  tree  method  has  been  in- 
cluded under  clearcutting  methods.  The  leaving  of  seed 
trees,  together  with  the  fact  that  the  seed  supply  is  furnished 
by  these  seed  trees  standing  on  the  area  cut  instead  of  by  trees, 
cut  in  the  clearing  operation  or  by  trees  standing  outside  the 
area  cleared,  warrants  the  separation  into  two  methods. 

Form  of  Forest  Produced.  —  The  seed  tree  method  re- 
quires the  same  form  of  stand  for  its  application  as  does 
clearcutting;  namely,  either  evenaged  or  if  containing  more 
than  one  age  class  with  all  trees  of  merchantable  size.  As  a 
result  of  the  seed  tree  method  an  evenaged  stand  is  produced. 
There  may  be  a  range  of  lo  to  20  years  in  age  between  the 
young  seedlings  which  start  on  the  cutover  area,  but  not 
enough  difference  to  prevent  the  stand  being  evenaged. 

For  a  number  of  years  immediately  following  the  first  cut- 
ting the  stand  presents  a  two-storied  appearance,  with  the 
seed  trees  forming  the  upper  story  and  the  reproduction  the 
understory. 

In  exceptional  cases  some  or  all  of  the  seed  trees  may  re- 
main throughout  the  rotation.  Where  this  occurs  the  stand 
may  be  termed  either  evenaged  or  two-storied  depending  on 
the  number  and  per  cent  of  the  area  occupied  by  the  seed  trees. 

Details  of  the  Method.  —  In  the  simplest  form  of  the  seed 
tree  method  the  seed  trees  are  left  standing  isolated  as  indi- 
viduals after  the  removal  of  from  80  to  over  90  per  cent  of  the 
volume  of  the  stand.  Natural  reproduction  springs  up  under 
and  around  the  seed  trees  in  sufficient  quantity  to  form  a 
new  stand.  If  conditions  are  favorable  a  single  seed  year 
may  suffice  to  accompHsh  this.  Frequently  the  seed  trees 
produce  several  crops  of  seed  before  regeneration  is  completed. 


46 


THE   SEED   TREE   METHOD 


It  is  evident  that  since  the  seed  trees  are  the  source  of  the 
seed  supply  they  must  be  selected  with  the  greatest  care. 
Windfirmness  is  a  primary  consideration  so  important  that 
the  scattered  seed  tree  method  cannot  be  used  if  the  seed 
trees  are  easily  thro\\Ti  or  broken  by  the  wind.  The  isolated 
position  of  the  trees  makes  them  particularly  susceptible  to 
such  injury.  With  shallow  rooted  species  or  on  moist  or 
shallow  soils  of  poor  holding  capacity  the  scattered  seed  tree 
method  is  inapplicable.  Even  if  the  seed  trees  are  not  up- 
rooted they  may  be  broken  off.     This  happens  where  the 


,?v^. 


<M 


Fig.  14. 

Good  {A)  and  poor  (5)  types  of  seed  trees.  Tree  A  with  its  wide  and  deep 
crown  is  wind  resistant,  capable  of  producing  abundant  seed  and  of  making 
increased  growth.  Tree  B  with  its  slim  bole  and  tuft-Uke  crown  is  weak  and 
liable  to  be  uprooted  or  broken  by  wind  or  scalded  by  sun  and  in  addition  is 
incapable  of  producing  large  seed  crops. 


stand  was  so  dense  before  cutting  as  to  produce  tall  slender 
trees.  Some  species  appear  more  susceptible  to  breakage  than 
others.  Trees  with  open  foliaged  crowns  are  more  likely  to 
stand  safely  against  wind  than  those  with  dense  crowns.  (See 
Fig.  14.) 


DETAILS   OF  THE  METHOD  47 

The  seed  trees  must  be  old  enough  to  produce  abundant 
fertile  seed.  The  age  at  which  seed  bearing  begins  in  closed 
stands  is  the  point  which  should  be  considered.  Besides 
being  old  enough  to  bear  seed  the  seed  trees  should  be  pref- 
erably of  the  dominant  or  at  least  of  the  co-dominant  classes. 
Trees  of  the  dominant  class  show  the  best  crown  development 
and  may  be  expected  to  produce  the  largest  amount  of  the 
best  seed  of  any  trees  in  the  stand.  The  dominant  trees  are 
also  among  the  stockiest  and  most  strongly  rooted  trees. 

Under  "Definition"  it  was  stated  that  the  seed  trees  might 
either  be  removed  afte'r  their  function  of  establishing  repro- 
duction was  performed  or  else  left  during  the  rotation  in  most 
cases  to  die  before  being  harvested  with  the  second  crop.  The 
selection  of  the  seed  trees  will  vary  depending  upon  which  of 
these  two  plans  is  to  be  followed. 

If  a  second  cutting  can  be  made  within  a  few  years  and  the 
seed  trees  saved,  then  fine  healthy  dominant  trees  presum- 
ably the  best  seed  producers  and  containing  valuable  timber 
may  be  selected.  Where  the  seed  trees  are  going  to  be  left 
and  must  be  considered  as  a  total  loss,  then  trees  of  a  lower 
commercial  value  may  have  to  be  chosen.  These  may  be 
the  deformed  or  limby  trees  or  trees  attacked  by  fungi. 
As  a  general  proposition  it  is  unsafe  and  unwise  to  leave  fun- 
gus infected  trees  if  it  can  be  avoided,  because  of  the  probable 
quaHty  of  the  seed  and  seedHngs  produced,  and  the  low  vigor 
in  resisting  disease  which  trees  from  such  stock  may  possibly 
inherit.  Definite  information  as  to  the  effect  on  future  tree 
generations  of  different  types  of  fungi  is  still  fragmentary. 

Investigations  ^  carried  on  at  the  Wind  River  Experiment 
Station,  Carson,  Washington,  with  Douglas  fir  indicate  that 
conkiness  caused  mainly  by  Trametes  pini  reduces  the  yield 
of  good  seed  per  bushel  of  cones  to  62  per  cent  of  the  normal 
and  decreases  the  height  growth  of  young  seedlings  in  the 


nOfEFTr  imnART 

N.  C. 

48  THE   SEED   TREE   IMETHOD 

nursery.  But  after  five  years  growth  in  field  plantations, 
seedlings  from  conky  trees  exceed  those  from  sound  trees  in 
height  growth.  This  particular  fungus  on  Douglas  fir,  as  it 
attacks  only  heartwood,  may  not  affect  the  vitality  of  the 
tree. 

Pearson's  study  of  "  the  Influence  of  Age  and  Condition  of 
the  Tree  upon  Seed  Production  in  Western  Yellow  Pine,"  ^ 
indicated  that  those  affected  with  heart  rot  were  apt  to  have 
a  slightly  higher  germination  per  cent  than  sound  trees,  while 
mistletoe  reduced  the  germination  per  cent.  Seed  from  young 
trees  (below  140  years)  gave  a  higher  germination  per  cent 
than  that  from  older  trees.  Nothing  is  reported  as  to  the 
quality  of  the  seedlings  produced  by  seed  from  these  various 
classes  of  trees. 

After  fixing  upon  the  kind  of  seed  trees  to  be  left  the  num- 
ber per  acre  must  be  decided.  The  amount  of  seed  produced 
per  tree  and  the  distance  to  which  seed  can  be  disseminated 
are  among  the  principal  determining  factors.  The  very  nature 
of  the  method  requires  that  it  be  applied  only  with  relatively 
light  seeded  species  relying  upon  wind  dissemination  of  the 
seed.  Ample  seed  to  restock  all  portions  of  the  area  must  be 
provided.  As  a  general  rule  with  light  seeded  species  satis- 
factory dissemination  of  seed  can  be  counted  on  for  a  distance 
from  the  tree  at  least  equal  to  the  height  of  the  tree.  With 
large  sized  individuals  of  a  decidedly  light  seeded  species  one 
tree  per  acre  may  be  enough.  The  same  species  in  small 
sized  second  growth  timber  may  require  ten  per  acre.  A 
prolific  seed  producer,  but  with  a  heavy  seed  may  need  a 
similar  number  to  insure  uniform  distribution.  With  site 
conditions  favorable  to  germination  and  establishment  of 
reproduction  fewer  seed  trees  will  be  needed  than  if  the 
reverse  is  true.  The  necessity  of  securing  reproduction  either 
in  one  or  during  several  seed  years  and  whether  the  seed 


PROPI^K        '''^'^'^^^ 


DETAILS   OF  THE   METHOD  49 

trees  will  be  cut  in  a  few  years  or  remain  also  affect  the  num- 
ber which  can  properly  be  left.  From  one  to  ten  seed  trees 
per  acre  may  be  regarded  as  the  usual  range. 

If  more  than  ten  are  left  the  crown  spread  of  the  seed  trees 
occupies  a  considerable  part  of  the  area  and  the  method 
begins  to  resemble  shelterwood.  At  the  other  extreme  a 
species  is  rarely  found  capable  of  disseminating  the  seed  and 
thoroughly  restocking  an  area  if  less  than  one  seed  tree  per 
acre  be  retained. 

When  a  species  is  dioecious,  it  will  be  necessary  to  provide 
for  the  leaving  both  of  female  and  male  trees.  The  cotton- 
wood  (populus  deltoides)  furnishes  an  example.  In  reproduc- 
ing this  species  under  the  scattered  seed  tree  method  it  is 
advised  that  one  female  tree  be  left  to  every  acre  and  one 
male  tree  to  every  four  acres. ^ 

In  order  to  secure  adequate  reproduction  on  all  parts  of  the 
area  uniform  distribution  of  the  seed  trees  should  be  attempted. 
It  is  more  important  to  select  the  proper  individuals  to  serve 
as  seed  trees  than  to  attain  an  absolutely  even  spacing.  Where 
the  topography  is  uneven  it  will  generally  be  best  to  leave  a 
majority  of  the  trees  on  the  higher  ground,  from  which  vantage 
points  they  can  scatter  seed  over  the  lower  areas. 

Destruction  of  the  seed  by  rodents  may  be  a  serious  factor.^ 
Where  the  supply  is  restricted  to  a  few  seed  trees  per  acre  the 
rodents  may  take  the  entire  crop. 

Just  as  in  the  case  of  the  clearcutting  method  provision  for 
an  abundant  seed  supply  is  not  sufficient;  for  in  addition, 
favorable  conditions  for  germination  and  early  growth  of 
seedlings  must  be  established  and  maintained  for  a  few  years. 
Failure  to  apply  the  scattered  seed  tree  method  successfully 
may  often  be  traced  to  neglect  of  this  requirement.^ 

Disposal  of  the  brush  left  by  the  lumbermen,  removal  of 
weeds,  vines,  shrubs  and  reproduction  of  undesired  species 


50  THE   SEED   TREE   METHOD 

and  treatment  of  the  soil  are  the  measures  by  which  the  germi- 
nation of  seeds  and  development  of  young  reproduction  may 
be  influenced.  For  details  see  page  29,  under  the  Clear- 
cutting  Method. 

The  scattered  seed  trees  assist  in  conserving  surface  moist- 
ure, and  in  protecting  reproduction  from  injury  by  frost. 

When  enough  seedlings  to  make  a  full  stand  have  become 
established,  the  purpose  for  which  the  seed  trees  were  left  is 
accomplished.  If  it  will  pay  financially  the  seed  trees  can 
now  be  removed  leaving  the  new  stand  to  develop  unham- 
pered. A  portion  of  the  reproduction  will  be  destroyed  in 
this  cutting  but  not  enough  to  seriously  affect  the  new  stand. 
Where  a  second  cutting  of  this  character  is  not  feasible  the 
seed  trees  are  allowed  to  grow.  Some  few  may  hve  to  be  cut 
when  the  new  crop  is  harvested  and  furnish  material  of 
exceptional  size  and  quality.  Most  of  them  will  succumb 
to  the  ravages  of  insects  or  fungi.  Trees  grown  through  life 
in  a  closed  stand  and  then  suddenly  placed  in  an  exposed 
position  as  seed  trees  suffer  through  changed  site  conditions 
and  are  apt  to  be  weakened,  suffer  sun  scald  or  become  stag- 
headed  and  are  susceptible  to  insect  and  fungi  attacks. 

The  seedlings  may  start  immediately  after  the  first  cutting 
or  not  for  several  years,  depending  on  the  occurrence  of  a  seed 
year.  If  enough  seedlings  do  not  appear  within  five  years  it  is 
unlikely  that  reproduction  can  be  secured  by  natural  means. 
Certainly  not  unless  the  expenditures  for  preparation  of  the 
site  are  repeated.     The  blanks  should  be  filled  by  planting. 

Modifications  of  the  Method.  —  Group  Seed  Tree  Method. 
One  of  the  common  variations  is  to  leave  the  seed  trees  in 
groups  instead  of  scattered  singly  over  the  area.  The  pur- 
pose of  so  doing  is  to  minimize  the  danger  of  the  seed  trees 
being  windthrown  or  broken.  It  is  based  on  the  theory  that 
a  group  of  trees  standing  together  will  stand  unharmed  against 


MODIFICATIONS   OF   THE   METHOD  5 1 

winds  which  would  overturn  or  break  the  same  trees  if  stand- 
ing singly.  This  is  probably  the  fact  where  all  the  trees  avail- 
able are  relatively  slender  and  small  crowned.  Such  trees  may 
have  greater  strength  as  a  group  than  singly.  In  opposition 
to  this  field  observations  indicate  that  sometimes  groups  offer 
a  greater  resistance  to  winds,^  which  are  thus  enabled  to  exert 
greater  force  against  the  group  and  often  cause  overturn  or 
break  allthe  trees  in  the  group.* 

The  size  of  the  seed  group  has  of  course  great  influence  in 
determining  its  windfirmness.  To  be  reasonably  immune 
from  windthrow  a  group  should  have  length  and  breadth  at 
least  equal  to  its  height.  On  exposed  ridges  or  in  moist 
ground  groups  of  this  size  might  be  overthrown.  Groups 
with  breadth  and  width  equal  to  their  height  are  impracti- 
cable, requiring  too  great  an  investment  for  securing  natural 
reproduction.  Seed  groups  as  ordinarily  employed  will  con- 
tain from  two  to  ten  trees. 

Except  in  reducing  danger  to  the  seed  trees  from  wind 
the  group  seed  method  has  nothing  to  recommend  it  in  con- 
trast to  scattered  seed  trees.  The  distribution  of  seed  to  all 
parts  of  the  area  must  be  less  even,  unless  a  larger  per  cent 
of  the  total  volume  of  the  stand  be  reserved  in  the  seed 
groups.  If  only  the  small  volume  percentage  be  retained  as 
in  the  scattered  seed  tree  method,  then  the  distance  between 

*  As  an  illustration  the  following  is  quoted  from  a  circular  letter,  SI  Pro- 
tection-weather, Windfall  Study,  dated  February  12,  1915,  sent  from  the 
Portland  office  to  Supervisors  of  National  Forests  in  District  6  of  the  U.  S. 
Forest  Service,  speaking  of  windfall  in  yellow  pine  on  a  certain  sale  area. 

"In  groups  of  five  or  more  trees  there  is  considerably  more  windfall  than 
where  the  trees  are  evenly  distributed.  Where  there  are  sixteen  or  more  trees 
in  a  group  the  loss  is  13.4  per  cent  greater  than  where  the  groups  are  smaller. 
A  good  deal  of  the  loss  in  groups  comes  from  firm  trees  being  knocked  over  or 
broken  oQ  by  windthrown  neighbors,  or  by  their  root  anchorage  being  weak- 
ened by  the  uprooting  of  adjacent  trees.  This  is  on  the  principle  that  groups 
of  trees  do  not  give  mutual  support,  but  do  give  mutual  resistance  to  the  wind." 


52  THE  SEED  TREE  METHOD 

groups  will  average  longer  than  between  single  seed  trees  and 
are  apt  to  become  so  great  as  to  prevent  dissemination  of  the 
seed  over  the  entire  area.  This  affects  reproduction  not  only- 
through  a  poorer  distribution  of  the  seed  but  also  by  reducing 
the  shght  amount  of  protection  to  soil  and  seedlings  afforded 
by  the  scattered  seed  trees.     (See  Fig.  15.) 

In  a  mixed  stand  a  windfirm  species  sometimes  can  be 
included  in  a  seed  group  for  the  purpose  of  furnishing  sup- 
port to  a  species  easily  windthrown  which  it  is  desired  to 
reproduce.  There  is  danger  of  course  that  the  windlirm 
species  may  estabHsh  its  own  reproduction. 

Reserve  Seed  Tree  Method.  —  In  certain  cases  the  seed  tree 
method  may  be  appHed  not  only  with  the  idea  of  securing  a 
new  crop  of  natural  reproduction  but  also  with  the  purpose 
of  reserving  a  portion  of  the  mature  stand  for  rapid  increment 
during  a  second  rotation.  In  this  modification  of  the  method 
the  seed  trees  are  selected  not  only  for  their  capacity  to  fur- 
nish seed  but  also  to  grow  rapidly,  and  remain  thrifty  during 
a  second  rotation.  At  the  end  of  this  second  rotation  the 
new  crop  is  ha'rvested  together  with  the  seed  trees  left  at  the 
beginning  of  the  rotation.  Some  timber  of  exceptional  size  is 
produced. 

The  reserve  seed  tree  method  cannot  be  used  with  every 
stand.  For  its  successful  application  the  stand  must  be  of 
moderate  age  when  reproduced  with  the  individual  trees  still 
thrifty  and  capable  of  withstanding  the  change  in  site  condi- 
tions, due  to  the  cutting,  and  of  responding  with  increased 
growth.  In  stands  past  maturity  this  method  cannot  be 
successfully  applied. 

Dominant  trees  of  as  little  present  commercial  value  as 
possible  are  chosen:  but  they  must  be  dominant,  thrifty  trees. 
As  a  rule  healthier  and  better  quahty  trees  are  left  as  seed 
trees  than  under  the  scattered  seed  tree  method.    The  num- 


MODIFICATIONS  OF   THE   METHOD 


53 


ber  of  reserve  seed  trees  may  vary  depending  upon  whether 
emphasis  is  placed  on  the  development  of  the  stand  or  on  the 
timber  to  be  secured  eventually  from  the  seed  trees.     If  the 


Group  Seed-tree  Method 


Scattered  Seed-tree  Method 


Group  of  I 
5  Trees    1 


Group  of 
4  Trees 


Clear  Cut  excepjt  the  Seed-trees 


Group  of 
4  Trees 


Fig.  15. 

A  comparison  of  the  group  and  scattered  seed  tree  methods  where  the  same 
number  of  trees  (and  volume)  are  left  in  the  stand  imder  each  of  the  methods. 
It  is  evident  that  dissemination  of  seed  cannot  be  so  uniform  where  the  seed 
trees  are  arranged  in  groups  as  when  distributed  singly.  The  shaded  areas 
"indicate  the  portions  of  the  tract  occupied  by  the  crowns  of  the  seed  trees. 

new  stand  is  to  develop  properly  the  reserve  seed  trees  must 
be  relatively  few.     If  production  of  large  timber  is  of  primary 


54 


THE   SEED   TREE   METHOD 


importance  the  seed  trees  may  be  left  as  close  together  as 
rapid  growth  of  the  individuals  will  warrant.  A  distance  of 
at  least  30  to  40  feet  should  be  left  between  the  crowns  of  the 
reserve  seed  trees.  This  allows  on  the  average  for  about  20 
to  30  trees  per  acre  as  a  maximum,  or  approximately  twice 
as  many  as  would  be  left  under  the  scattered  seed  tree  method. 

The  reserve  seed  tree  method  maintains  a  two  storied  form 
of  forest.     (See  Fig.  16  ) 

The  advantages  of  the  reserve  as  contrasted  to  the  scat- 
tered  seed    tree   method   are   that:    better   reproduction   is 


Fig.  16. 

A  stand  ready  to  cut  containing  reserve  seed  trees.  The  form  is  two-storied. 
The  large  reserve  seed  trees  will  be  removed  and  thrifty  individuals  selected 
from  the  lower  story  to  remain  during  another  rotation. 

obtained  due  to  the  larger  seed  supply  and  increased  protec- 
tion furnished  by  the  greater  number  of  trees,  and  production 
of  some  large  sized  timber  is  secured. 

The  understory  when  harvested,  is  apt  to  be  of  low  yield 
and  poor  quality  due  to  interference  from  the  upper  story. 

Fire  Seed  Trees.  —  It  has  been  the  practice  of  the  United 
States  Forest  Service  to  retain  on  certain  cutover  areas,  single 
scattered  trees,  which  may  be  termed  fire  seed  trees.  These 
trees  have  been  left  after  the  final  cuttings  in  various  modifi- 
cations of  the  clearcutting,  seed  tree  and  shelterwood  methods. 
In  most  instances  either  reproduction  already  was  estabhshed 
at  the  time  the  fire  seed  trees  were  left  in  their  isolated  posi- 
tion or  other  sources  of  seed  supply  were  counted  on  to  com- 


ADVANTAGES   AND    DISADVANTAGES  55 

plete  the  reproduction.  The  purpose  of  the  fire  seed  trees  is 
then  not  primarily  to  establish  the  second  crop.  These  trees 
are  left  as  a  measure  of  fire  insurance.  In  case  the  reproduc- 
tion is  destroyed  by  fire  the  seed  trees,  due  to  their  size  and 
hardiness,  are  expected  to  escape  and  to  provide  the  seed 
for  restocking  the  burn.  In  some  cases  occasional  large  thick- 
barked  Douglas  fir  which  would  escape  fire  have  been  left 
together  with  thrifty  younger  seed  trees  which  would  be 
killed  by  a  severe  fire.  Species  which  are  exceptionally  fire 
resistant  make  ideal  fire  seed  trees.  Western  larch  is  one  of 
the  best  examples.  This  species  has  been  left  as  fire  seed 
trees  in  certain  instances  in  the  western  white  pine  type  in 
northern  Idaho. 

Fire  resistant  species  cannot  always  be  found  to  serve  as 
fire  seed  trees.  When  less  resistant  species  are  used  there  is 
a  question  whether  the  fire  which  destroys  the  reproduction 
will  not  also  kill  the  seed  trees.  It  is  also  an  open  question 
as  to  whether  the  fire -seed  trees  can  successfully  restock  a 
bare  burned  area.  If  site  conditions  are  unfavorable  to  nat- 
ural reproduction  it  is  unreasonable  to  expect  restocking  by 
scattered  seed  trees.  If  site  conditions  are  favorable  for 
natural  reproduction  it  follows  that  artificial  methods  are 
possible.  This  being  the  case  it  is  questionable  whether  the 
financial  investment  in  leaving  fire  seed  trees  (unless  of  an 
exceptionally  fire  resistant  species)  is  always  justified.  It 
may  be  cheaper  to  cut  clear  and  to  replace  by  artificial  meth- 
ods the  occasional  bodies  of  reproduction  consumed  by  fire. 
Nevertheless  when  the  fire  danger  is  great  and  artificial  re- 
generation on  a  large  scale  following  fires  might  be  needed 
over  extensive  areas  the  leaving  of  fire  seed  trees  is  fully 
justified. 

Advantages  and  Disadvantages  of  the  Seed  Tree  Method.— 
Advantages.  —  i.   Logging  is  concentrated  on  relatively  small 


56  THE   SEED   TREE   METHOD 

areas.     This  tends  to  keep  logging  and  transportation  costs 
low.  • 

2.  Furnishes  a  bare  exposed  site  for  the  start  of  natural 
reproduction  and  hence  may  be  a  goo^  method  for  those 
species  which  require  such  a  germinating  bed. 

3.  It  stands  next  to  clearcutting  as  a  simple  and  easy 
method  to  practice. 

4.  The  period  of  regeneration  in  each  stand  being  confined 
to  a  small  portion  of  the  rotation  permits  use  of  the  area  for 
grazing  during  the  remainder  of  the  time. 

5.  As  contrasted  to  clearcutting  with  natural  reproduction 
it  provides  better  control  of  the  species  in  the  reproduction 
on  the  cutover  area  since  only  individuals  of  species  which 
it  is  desired  to  reproduce  are  left  for  seed  trees. 

6.  As  compared  with  shelterwood  or  clearcutting  in  two  or 
more  operations  the  seed  tree  method  may  be  used,  provided 
the  trees  are  all  of  merchantable  size,  under  more  expensive 
logging  conditions,  since  it  does  not  absolutely  require  a 
second  cutting. 

Disadvantages.  —  i.  The  virtual  clearing  of  the  area  in- 
duces conditions  which  for  most  species  are  adverse  to  the 
growth  of  seedlings  and  render  uncertain  establishment  of  a 
satisfactory  reproduction.  (See  under  Clearcutting  Method 
—  Disadvantage  No.  i  for  further  details.) 

In  the  seed  tree  method  exposure  of  the  site  takes  place  to 
a  degree  only  slightly  less  than  in  clearcutting,  with  similar 
disadvantages. 

2.  Affords  poor  protection  against  erosion,  landsHdes,  snow- 
slides  and  rapid  runoff  of  water. 

3.  While  aesthetically  the  seed  tree  method  is  to  be  pre- 
ferred to  clearcutting  it  does  not  commend  itself  from  the 
standpoint  of  forest  aesthetics  as  compared  with  shelterwood 
and  selection. 


APPLICATION  OF  THE  METHOD  •  57 

4.  Due  to  the  danger  from  wind  in  which  isolated  trees  are 
placed,  the  seed  tree  method  is  appHcable  only  with  deep 
rooted  species. 

5.  The  method  is  restricted  to  species  which  have  light 
wind  disseminated  seeds  capable  of  germinating  on  clearings 
and  developing  thrifty  seedlings  under  such  circumstances. 

6.  The  supply  of  seed  is  relatively  scanty,  compared  with 
that  available  in  the  shelterwood  and  selection  methods,  coming 
as  it  does  from  a  few  seed  trees. 

7.  As  contrasted  to  clearcutting  the  seed  tree  method  is  not 
applicable  in  stands  of  overmature  timber.  Such  stands  may 
be  past  the  age  for  producing  abundant  crops  of  fertile  seed. 
The  individual  trees  due  to  their  large  size  and  age  are  not 
well  suited  to  be  left  as  seed  trees. 

The  disadvantages  with  the  exception  of  numbers  4  and  7  are 
overcome  to  some  extent  when  the  reserve  seed  method  is  used. 

Application  of  the  Method.  —  The  seed  tree  method  so 
far  has  not  been  looked  upon  with  favor  in  North  America. 
This  is  due  principally  to  the  bad  impression  created  by  a 
few  prominent  examples  ^  of  unsuccessful  application.  Ordi- 
narily such  failures  have  been  caused  by  applying  the  method 
under  conditions  demanding  some  other  method  or  by  neglect- 
ing to  properly  attend  to  the  details  of  application. 

The  scattered  seed  tree  method  was  used  in  certain  stands 
of  white  and  Norway  pine  {Pinus  resinosa)  included  in  the 
Minnesota  National  Forest.  This  timber  was  evenaged  old 
growth  and  as  such  not  suited  for  reproduction  by  the  seed 
tree  method.  Too  few  seed  trees  were  left  (due  to  legal 
restrictions)  and  those  remaining  were  often  poorly  distrib- 
uted. The  preparation  of  the  site  for  the  establishment  and 
development  of  reproduction  was  neglected.  Is  it  surprising 
that  the  results  so  far  as  securing  reproduction  went  were 
largely  negative? 


58  THE  SEED  TREE  IMETHOD 

Eventually  the  seed  tree  method  should  find  frequent  and 
successful  use  in  forest  regions  where  climate  favors  natural 
reproduction.  In  regions  where  natural  reproduction  is  seri- 
ously handicapped  by  adverse  climatic  and  site  factors  the 
seed  tree  method  with  its  scanty  seed  supply  and  exposure  of 
the  site  is  out  of  place.  Several  of  the  southern  pines,  in- 
cluding loblolly,  shortleaf  and  slash  pines,  should  be  easily 
reproduced  by  this  method.  Among  the  broadleaf  trees,  Cot- 
tonwood, in  some  cases,  can  be  managed  by  leaving  seed 
trees. 

Since  the  seed  tree  method  can  be  applied  with  only  one 
cutting  which  removes  nearly  all  the  timber  it  may  find  use 
where  methods  requiring  more  cuttings  are  too  expensive. 

REFERENCES 

1.  Willis,  C.  P.,  and  Hofman,  J.  V.  A  Study  of  Douglas  Fir  Seed.  Pro- 
ceedings of  the  Society  of  American  Foresters,  Vol.  X,  1915,  pp.  141-164;  and 
KR.4EBEL,  C.  J.  Choosing  the  Best  Tree  Seeds.  Journal  of  Heredity  (Organ 
of  the  American  Genetic  Association),  Vol.  VIII,  pp.  483-492. 

2.  Pearson,  G.  A.  The  Influence  of  Age  and  Condition  of  the  Tree  upon 
Seed  Production  in  Western  Yellow  Pine.  Circular  196,  Forest  Service, 
United  States  Department  of  Agriculture,  Washington,  191 2. 

3.  Williamson,  A.  W.  Cottonwood  in  the  Mississippi  Valley.  Bulletin 
24,  United  States  Department  of  Agriculture,  Washington,  1913,  pp.  31-33. 

4.  Kenety,  W.  H.  Report  of  Cloquet  Forest  Experiment  Station.  Bulle- 
tin 169,  The  University  of  Minnesota,  St.  Paul,  191 7,  pp.  59-60. 

5.  MuNGER,  T.  T.  Western  Yellow  Pine  in  Oregon.  Bulletin  418,  United 
States  Department  of  Agriculture,  Washington,  191 7,  p.  15. 

6.  Frothingham,  E.  H.  White  Pine  under  Forest  Management,  Bulletin 
13,  United  States  Department  of  Agriculture,  Washington,  1914,  p.  46. 

Howe,  C.  D.  Address  delivered  before  B.  C.  Forest  Club.  Proceedings  of 
the  British  Columbia  Forest  Club,  Vol.  2,  Victoria,  1916,  pp.  83-87. 

Mattoon,  W.  R.  Shortleaf  Pine:  Its  Economic  Importance  and  Forest 
Management.  Bulletin  308,  U.  S.  Department  of  Agriculture,  Washing- 
ton, 1915,  pp.  45-46. 

Recknagel,  a.  B.  Some  Aspects  of  European  Forestry.  Forestry  Quarterly, 
Vol.  XI,  1913,  p.  475. 


CHAPTER  V 
THE   SHELTERWOOD   METHOD 

Definition.  —  The  principle  of  the  shelterwood  method  in- 
volves the  removal  of  the  stand  by  a  series  of  partial  cuttings, 
resembling  thinnings,  that  remove  the  entire  stand  within  a 
period  of  years  which  is  a  small  fraction  of  the  rotation  age. 
Natural  reproduction  starts  under  the  protection  of  the  older 
stand  and  is  finally  released  from  this  shade  and  protection 
when  able  to  endure  the  exposure.  It  is  a  logical  further  de- 
velopment of  the  seed  tree  method  retaining  large  numbers  of 
seed  trees  instead  of  a  few. 

The  terms  "stand"  and  ''compartment"  method  have  been 
used  to  describe  the  shelterwood  method. 

Form  of  Forest  Produced.  —  The  shelterwood  method  is 
best  applied  in  evenaged  stands,  though  it  can  be  used  in 
those  of  irregular  form  where  merchantable  age  classes  pre- 
dominate. It  produces  an  evenaged  stand,  thus  resembling 
the  clearcutting  and  seed  tree  methods.  In  some  cases  the 
reproduction  cuttings  may  extend  (when  the  rotation  is  long) 
over  a  period  of  forty  to  fifty  years,  which  tends  to  create  a 
wider  range  in  the  ages  of  the  individual  trees  than  occurs  in 
the  other  two  methods.  Even  with  a  long  regeneration  period 
the  stand  still  remains  essentially  evenaged  in  character. 

Details  of  the  Method.  —  When  using  the  shelterwood 
method,  as  its  name  implies,  reproduction  is  secured  under 
the  shelter  of  a  portion  of  the  old  stand.  Besides  furnishing 
the  seed  the  old  stand  affords  protection  to  the  young  seed- 
lings.    A  time  finally  comes  when  this  shelter  instead  of  being 

59 


6o  THE  SHELTERWOOD  METHOD 

a  benefit  is  a  hindrance  to  the  growth  of  the  seedlings.  It 
becomes  necessary  to  remove  the  remainder  of  the  old  stand, 
giving  the  new  stand  possession  of  the  area  and  opportunity 
to  develop  in  the  evenaged  form. 

The  whole  process,  including  the  securing  of  natural  repro- 
duction, its  protection  and  final  release  from  shelter,  is  accom- 
plished within  a  relatively  short  period. 

Several  cuttings  (at  least  two  and  sometimes  six  to  ten) 
under  intensive  management,  are  required  in  applying  the 
shelterwood  method.  They  may  be  classed  under  three 
heads,  as  follows: 

Preparatory  cuttings  which  prepare  for  reproduction.  ' 
Seed  cuttings  which  accomplish  the  reproduction. 
Removal  cuttings  which  aid  the  development  of  the 
seedlings. 

The  detailed  appHcation  of  the  method  can  best  be  pre- 
sented by  taking  up  each  of  these  cuttings  in  turn. 

Preparatory  Cuttings.  —  If  natural  reproduction  is  to  start 
under  the  old  stand  a  supply  of  seed  must  be  available  and 
site  conditions  be  favorable  for  germination  of  seed  and  estab- 
Hshment  of  seedlings. 

With  the  entire  stand  available  as  a  source  of  seed  supply 
there  should  be  an  abundance  of  seed  for  restocking  the  area. 
In  very  dense  stands  where  the  best  individual  trees  possess 
short  narrow  crowns  and  are  poor  seed  producers,  preparatory 
cuttings  may  be  needed  to  encourage  an  enlargement  of  the 
crowns,  to  assist  assimilation  and  as  a  consequence  stimulate 
an  increased  production  of  seed.  Ordinarily  preparatory  cut- 
tings are  not  needed  for  this  purpose.  Their  principal  func- 
tion is  to  create  ideal  site  conditions  for  the  germination  of 
seed.  In  closed  stands  there  is  apt  to  be  too  thick  and  dry  a 
forest  floor  for  seedlings  to  get  their  roots  down  into  the  soil. 


DETAILS   OF  THE   METHOD  6l 

Decomposition  of  the  litter  can  be  hastened  by  admitting 
through  cutting  more  light,  heat  and  a  free  circulation  of  air. 
This  is  accomplished  by  the  preparatory  cutting^  Too  rapid 
and  complete  disintegration  of  the  humus  is  possible  and  may 
allow  a  growth  of  grass  and  weeds  to  spring  up.  The  right 
condition  of  seed  bed  for  each  species  must  be  known  and  the 
severity  of  the  preparatory  cutting  governed  accordingly.  (See 
Figs.  17  and  18.) 

When  the  mineral  soil  appears  in  spots  here  and  there  and 
small  patches  of  grass  and  herbs  start,  then  ordinarily  the 
litter  is  sufficiently  decomposed. 

A  minor  object  of  the  preparatory  cutting  may  be  in  certain 
cases  to  develop  windfirm  trees  which  can  safely  be  left  iso- 
lated in  the  later  cuttings.  This  is  especially  necessary  in 
dense  stands  where  the  crown  development  of  the  individual 
trees  is  poor. 

It  requires  from  three  to  ten  years  to  accomplish  the  results 
for  which  the  preparatory  cuttings  are  made. 

Preparatory  cuttings  range  in  number  from  one  to  several. 
In  certain  cases  no  preparatory  cuttings  at  all  are  demanded. 
This  is  apt  to  be  the  case  in  stands  which  have  been  syste- 
matically thinned  previous  to  the  reproduction  period.  The 
number  of  cuttings  depends  on  the  length  of  time  required 
to  accomplish  the  purposes  for  which  they  are  made  and  upon 
the  necessity  for  making  openings  in  a  given  stand  only 
gradually. 

The  trees  cut  in  preparatory  cuttings  may  be  selected  from 
among  five  classes ;  namely : 

Diseased  and  defective  trees. 

Overtopped  trees, 

Trees  with  over-developed  and  spreading  crowns. 

Slender  small  crowned  trees  liable  to  be  windthrown,  and 

Those  of  undesirable  species. 


DETAILS   OF   THE   METHOD  63 

This  leaves  principally  dominant  and  co-dominant  trees.  Or- 
dinarily it  is  impossible  to  remove  all  the  trees  in  these  five 
classes  without  taking  out  a  greater  proportion  of  the  stand 
than  is  warranted  for  accomplishing  the  purpose  of  the  pre- 
paratory cuttings.  Hence  some  of  them  must  be  left  until 
later  cuttings.  The  trees  left  should  be  so  spaced  as  to  pro- 
vide an 'even  crown  cover  over  the  area  with  spaces  not  more 
than  three  to  five  feet  in  width  as  a  maximum  between  the 
edges  of  the  crowns.  In  volume  from  20  to  30  per  cent  of  the 
stand  should  be  cut  in  the  preparatory  cuttings. 

Seed  Cuttings.  —  The  purpose  of  the  seed  cuttings  (of  which 
there  should  be  only  one)  is  to  establish  reproduction.  The 
seedbed  has  been  brought  into  excellent  condition  for  the  start 
of  young  seedlings.  A  seed  year  is  awaited  and  when  it  arrives 
a  cutting  is  made  preferably  just  after  the  seed  has  matured. 
The  logging  serves  to  work  the  seed  thoroughly  into  the  thin 
humus  and  mineral  soil.  It  finds  here  an  ideal  germinating 
bed  with  an  abundance  of  light  and  heat  made  available  as 
a  consequence  of  the  reduction  in  the  forest  cover. 

If  a  perfect  seedbed  has  been  created  and  a  plentiful  supply 
of  seed  deposited  upon  it  and  mixed  with  the  soil  then  a  com- 
plete reproduction  may  be  secured.  Unfortunately  such  a 
combination  is  difficult  of  attainment.  If  it  is  apparent  that 
the  preparatory  cuttings  have  failed  to  create  the  proper 
seedbed  conditions  they  may  be  produced  artificially.  Such 
methods  as  preparing  seed  spots  at  close  intervals,  plowing 
furrows  under  the  trees,  or  turning  in  hogs  to  work  up  the  soil 
and  humus  may  be  employed.  For  further  details  in  reference 
to  treatment  of  the  site  see  under  Clearcutting,  page  30. 

Rarely  is  it  necessary  with  the  shelterwood  system  to  re- 
sort to  artificial  restocking  of  failed  places.  Action  of  this 
sort  would  be  taken  only  as  a  last  resort  when  it  was  seen 
that  natural  seeding  had  proved  a  failure. 


64  THE  SHELTERWOOD  METHOD 

The  trees  selected  for  removal  in  the  seed  cutting  are  of  the 
same  general  classes  as  those  taken  in  the  preparatory  cuttings. 
Should  it  be  necessary  to  take  out  more  trees  than  those  kinds 
designated  for  removal  in  preparatory  cuttings  the  poorer 
individuals  in  the  co-dominant  and  dominant  classes  are  cut. 

The  severity  of  the  seed  cutting  is  governed  by  the  distance 
to  which  seed  may  be  distributed  and  by  the  amount  of  shade 
which  it  is  necessary  to  maintain  in  order  to  assist  germina- 
tion and  to  protect  seedlings  from  drought,  frost  and  rank 
growths  of  grass  and  herbs.  In  as  much  as  the  balance  of 
the  stand  must  be  removed  after  reproduction  is  started  and 
with  considerable  injury  to  the  latter,  it  is  advantageous  to 
take  off  as  much  of  the  old  stand  as  possible  in  the  seed  cut- 
ting. The  amount  removed  should  range  from  25  to  50 
per  cent  of  the  volume  of  the  original  stand  before  preparatory 
cuttings  were  begun. 

It  is  not  necessary  that  the  distribution  of  the  trees  left  be 
absolutely  uniform,  although  reasonable  uniformity  is  at- 
tempted. In  fact  an  uneven  distribution,  provided  the  open 
areas  among  the  old  timber  are  kept  small,  may  not  be  un- 
favorable to  the  seedlings  in  their  competition  with  the  older 
trees  for  soil  moisture.  In  the  seed  cutting  advantage  is 
taken  of  all  groups  of  advance  growth,  which  may  have 
started  accidentally  or  as  an  unlooked  for  result  of  the  pre- 
paratory cuttings.  Over  such  groups  the  seed  cutting  is 
heavy  and  may  even  remove  all  the  old  timber.  Usually 
three  to  five  years  elapse  before  the  seed  cutting  is  followed 
by  a  removal  cutting. 

Removal  Cuttings.  —  Removal  cuttings  have  as  their  object 
the  gradual  uncovering  of  the  new  crop  which  finally  is  given 
complete  possession  of  the  area.  There  may  be  one  or 
(usually)  several  removal  cuttings,  the  last  of  which  is  called 
the  final  cutting.     The  severity  of  the  removal  cuttings  and 


-3  .3 
to 


6s 


66  THE   SHELTERWOOD   METHOD 

the  intervals  at  which  one  follows  the  other  are  governed  by 
the  degree  to  which  the  young  stand  needs  protection  or  is 
suffering  from  too  much  shelter. 

After  the  reproduction  is  estabhshed  it  is  watched  for  indi- 
cations of  poor  condition.  Such  points  especially  as  un- 
healthy color  of  the  foliage,  falhng  off  of  height  growth  and 
bending  aside  toward  the  light  are  taken  as  showing  the  need 
of  less  shade  and  competition.  This  condition  of  the  repro- 
duction is  not  hkely  to  be  found  uniformly  over  the  whole 
area,  at  any  one  time.  On  the  contrary  a  patch  here  and  a 
patch  there  will  probably  require  treatment.  Hence  the  re- 
moval cuttings  are  not  made  evenly  over  the  whole  area.  A 
group  may  be  cut  clear  here,  a  few  trees  thinned  out  in  other 
places,  while  elsewhere  there  may  be  no  cutting.  A  few  years 
later  other  places  need  a  similar  cutting,  and  the  process  con- 
tinues until  at  last  all  the  old  tunber  is  harvested  (see  Fig.  19). 

Removal  cuttings  are  hkely  to  be  needed  at  intervals  of 
two  to  five  years  and  to  cover  a  period  of  from  two  to  20 
years.  They  utiHze  the  remaining  25  to  50  per  cent  of  the 
volume  of  the  original  stand. 

Each  removal  cutting  does  some  injury  to  the  young  stand. 
Where  proper  methods  are  enforced  in  felling  trees  and  in 
hauling  the  logs  to  the  roads  this  injury  is  not  of  serious 
consequence.  Hauling  out  the  logs  with  single  horses  makes 
narrow  lanes  through  the  reproduction  and  minimizes  the 
damage  from  this  source.  While  the  trees  in  being  felled 
will  destroy  many  seedlings,  yet  this  loss  will  rarely  interfere 
with  a  full  stocking  of  the  area. 

Modifications  of  the  Method.  —  The  shelterwood  method 
may  be  applied  hi  a  given  stand  either: 

(a)  Uniformly  over  the  entire  stand.  —  the  unifonn  method 

(b)  In  strips,  • —  strip  shelterwood 

(c)  In  groups  or  patches,  —  group  shelterwood. 


4J 

n 

^ 

o 

aJ 

s 

(Ti 

H 

a 

a 

^' 

5 

rrl 

T) 

M 

•S  ■?  c 

rt      O      4J 


3  B 


67 


68  THE  SHELTERWOOD   METHOD 

The  details  as  already  described  relate  particularly  to  the 
uniform  application  of  the  method  although  in  the  strip  and 
group  modifications  essentially  the  same  procedure  is  fol- 
lowed except  that  a  given  cutting  is  extended  over  a  portion 
only  instead  of  over  the  entire  stand. 

Strip  Shelterwood  Method.  —  In  this  modification  of  the 
shelterwood  method  the  stand  is  divided  into  strips  laid  out 
at  right  angles  to  the  prevailing  winds.  Starting  with  the 
strip  on  the  lee  side  of  the  stand  the  cuttings  are  made  to 
progress  against  the  wind. 

The  first  strip  receives  a  preparatory  cutting.  After  a  few 
years  it  may  receive  another  preparatory  cutting  or  a  seed 
cutting,  while  at  the  same  time  the  adjoining  strip  is  given  a 
first  preparatory  cutting.  A  few  years  later  the  first  strip 
may  receive  a  seed  cutting  or  a  first  removal  cutting,  the 
second  strip  a  second  preparatory  cutting  or  a  seed  cutting 
and  a  third  strip  be  given  a  first  preparatory  cutting.  In 
this  manner  (see  Fig.  20  and  Fig.  21),  the  series  of  cuttings 
progress  strip  by  strip  across  the  stand. 

There  appear  to  be  two  advantages  of  the  strip  arrange- 
ment over  the  uniform  application.  Better  protection  is 
afforded  against  windfall  since  part  of  the  stand  is  kept  intact 
as  a  windbreak  and  no  considerable  areas  on  which  the  trees 
stand  isolated  are  left  at  any  one  time.  Better  or  quicker 
reproduction  should  be  secured  because  of  the  extra  amount 
of  seed  furnished  by  the  trees  on  the  adjoining  strip  which  is 
less  heavily  cut,  and  because  the  side  shade  and  protection 
against  evaporation  afforded  by  this  strip  should  conserve 
the  soil  moisture. 

Since  complete  reproduction  can  be  counted  on  in  less  time 
the  strip  modification  allows  a  decrease  in  the  number  of 
cuttings  required  to  remove  the  whole  stand  and  consequently 
those  which  are  made  may  be  heavier. 


MODIFICATIONS  OF  THE  METHOD 


69 


Fig.  20, 

Diagram  of  a  stand  reproduced  by  the  shelterwood  method,  each  cutting 
being  applied  uniformly  to  the  entire  area.     Compare  with  Figs.  21  to  24. 


Cutting  Series  No.  1 
A 


Cutting  Series  No.  2 

A 


Y 

1        j       2        1        3        j       4        1 

1         1 

3        I        3 

4 

illsiliiillsiliiisl! 

1 

.2^    -    :   !.Sr    :   ^  |.S:    r    :  I.S:   .   e   I 

1 

j 

ry  Cutting 
ry  Cuttina: 
ry  Cutting 
ry  Cutting 

1 

1 
Cutting* 

1 

1, 

made  in  same  Arrai 

gement 

and  Tim.e 

1 

1 

as  in  Cu|;ting  Serie 

i  No.  1 

rt-    '     ^IcSi:    r.rtic    Cics:    :-    1 

1 

1 

Received 
Received 
Received 
Received 

! 

1 
1 

Fig.  21. 

Diagram  of  a  stand  reproduced  by  the  strip  shelterwood  method.  Two  cut- 
ting series  are  used.  The  period  of  regeneration  is  20  years  in  length  and  the 
stand  is  kept  in  the  evenaged  form. 


70  THE  SHELTERWOOD   METHOD- 

The  width  of  the  strips  depends  upon  the  danger  from 
windfall  and  upon  the  extent  to  which  side  shade  and  con- 
servation of  soil  moisture  are  desirable. 

Strips  should  rarely  be  less  than  loo  feet  in  width,  and  if 
wider  than  500  to  800  feet  lose  the  inherent  characteristics 
of  a  strip  shelterwood  cutting. 

The  length  of  the  period  of  regeneration  remains  the  same 
as  under  the  uniform  application  of  the  method.  If  the  strips 
must  be  made  narrow  and  the  stand  is  a  large  one,  it  may  be 
necessary  to  establish  several  cutting  series  in  order  to  com- 
plete the  reproduction  cuttings  within  the  allotted  period. 
For  discussion  of  the  use  of  several  cutting  series  refer  to  clear- 
cutting  in  strips  on  page  32. 

Strip  shelterwood  does  not  necessarily  cause  any  greater 
range  of  age  between  the  individuals  of  the  new  stand  than 
does  application  uniformly  over  the  entire  area,  since  the 
period  of  regeneration  is  the  same  in  the  two  cases.  The 
differences  in  age  are  not  noticeable  because  the  average 
ages  of  the  trees  on  the  strips  first  operated  are  greater  than 
those  on  the  strips  in  which  cuttings  start  later.  The  total 
range  of  ages  is  so  small  as  not  to  interfere  with  the  evenaged 
character  of  the  stand. 

Wagfier's  "  Border  Cuttings.^'  —  Wagner  ^  developed  in 
practice  on  a  forest  in  Wurtemberg  a  modification  of  the  strip 
shelterwood  method  which  in  this  country  has  received  the 
name  "Border  Cuttings."^  Heralded  as  something  quite 
new  in  silviculture  it  reduces  in  the  last  analysis  to  strip 
shelterwood  with  exceedingly  narrow  strips  (less  than  100 
feet  in  width). 

Group  Shelterwood  Method.  —  Commonly  in  evenaged  for- 
ests, particularly  in  those  which  have  undergone  thinning  or 
had  their  regularity  disturbed  by  natural  agencies  such  as 
wind,  insects  or  fungi,  it  happens  that  when  the  beginning  of 


MODIFICATIONS   OF   THE   METHOD  7 1 

the  period  of  regeneration  is  reached,  groups  of  advance  re- 
production are  already  present.  The  groups  may  range  from 
a  few  trees  to  considerable  areas  of  young  growth  and  from 
seedlings  a  few  years  old  up  to  trees  of  sapling  size. 

Where  this  condition  exists  the  reproduction  cuttings  are 
made,  not  uniformly  over  the  area,  but  irregularly  and  en- 
tirely with  reference  to  the  special  requirements  of  each  group 
of  advance  reproduction.  The  first  cutting  made,  which  may 
be  called  a  primary  cutting,  combines  removal  cuttings  (in- 
cluding the  final  cutting),  seed  cuttings  and  preparatory  cut- 
tings all  in  the  one  operation.  Where  the  advance  reproduc- 
tion is  largest  the  cutting  removes  all  of  the  old  trees  and 
is  thus  a  final  cutting.  Where  reproduction  shows  indica- 
tions of  too  severe  competition  with  the  overwood,  but  is  not 
yet  capable  of  being  left  without  some  protection,  a  removal 
cutting,  taking  part  of  the  old  timber,  is  made.  Where  re- 
production has  not  started  as  yet,  but  seedbed  conditions 
are  suitable  for  its  estabhshment,  a  seed  cutting  is  executed. 
Finally,  in  the  denser  portions  of  the  stand  if  any  cutting  at 
all  is  made,  it  will  be  in  the  nature  of  a  preparatory  cutting. 
Ordinarily  each  group  of  advance  reproduction  serves  as  a 
center  from  which  the  cutting  radiates.  Over  the  higher  re- 
production at  the  center  of  the  group  a  final  cutting  is  made. 
In  a  belt  surrounding  this  center,  removal  cuttings  are  made 
decreasing  in  severity  as  the  younger  reproduction  toward 
the  edges  of  the  group  is  reached.  In  a  belt  encircling  the 
group  of  reproduction  a  seed  cutting  takes  place,  while  beyond 
this  area  a  ring  of  forest  receives  a  preparatory  cutting.  Be- 
yond this  ring  the  forest  remains  untouched. 

After  a  few  years  when  conditions  indicate  its  desirability, 
another  cutting  called  a  secondary  cutting  is  made  of  the 
same  character  as  the  primary  cutting,  uncovering  addi- 
tional areas  of  reproduction  and  extending  the  removal,  seed 


72  THE  SHELTER  WOOD   METHOD 

and  preparatory  cuttings  over  additional  territory.  (See 
Fig.  2  2  and  Fig.  23.) 

At  intervals  additional  successive  cuttings  are  made  stead- 
ily broadening  the  area  cut  over  until  finally  the  various 
groups  which  served  as  original  starting  points  are  expanded 
until  they  merge  one  with  the  other  and  the  entire  stand  is 
reproduced.     (See  Fig.  24.) 

The  period  allotted  to  reproduction  cuttings  under  the 
group  method  may  be  of  the  same  length  as  that  used  in  uni- 
form and  strip  shelterwood,  but  since  advance  reproduction 
(often  20  to  30  years  old)  is  already  present  when  repro- 
duction cuttings  commence,  the  range  in  age  between  indi- 
vidual trees  of  the  new  stand  is  apt  to  be  wider  than  in  the 
two  latter  methods.  The  stand  can  in  most  cases  still  be 
classed  as  evenaged. 

Group  shelterwood,  when  employed  on  a  long  rotation  with 
a  correspondingly  long  period  of  regeneration,  approaches  in 
form  of  forest  that  produced  under  the  selection  method,  as 
will  be  better  understood  after  consideration  of  the  chapter  on 
selection. 

Extensive  versus  Intensive  Application  —  The  discussion  of 
the  shelterwood  method  has  up  to  this  point  related  particu- 
larly to  its  intensive  application. 

Shelterwood,  requiring  as  it  does  several  cuttings  on  the 
same  area  within  a  relatively  short  period,  inherently  is  best 
adapted  for  employment  under  conditions  allowing  intensive 
management.  Only  in  regions  where  the  market  allows  sale 
of  lower  grade  products,  such  as  cordwood,  and  where  a  per- 
manent road  system  exists,  that  permits  easy  access  to  all 
parts  of  the  forest,  can  the  shelterwood  method  be  applied 
intensively. 

The  method  meets  so  well  the  silvical  requirements  for  re- 
production of  several  important  species  that  modifications  to 


MODIFICATIONS   OF   THE   METHOD 


75 


Fig.  24. 
Arrangement  of  the  cuttings  in  a  stand  reproduced  by  the  group  shelterwood 
method.     Advance  reproduction  was  present  on  areas  marked  "1"  before  the 
cutting. 

permit  its  application  in  an  extensive  way  under  poor  market 
conditions  and  in  the  absence  of  permanent  roads  have  been 
developed. 

Smnmarized,  these  modifications  consist  in: 
Reducing  the  total  number  of  cuttings  to  two  or  three, 
Lengthening  the  period  of  regeneration,  and 
Omitting  all   refinements   for   securing   a   complete    re- 
stocking. 


76  THE   SHELTERWOOD   METHOD 

Under  extensive  application  no  preparatory  cuttings  are 
made.  Instead  of  such  cuttings  the  natural  opening  up  of 
the  stand  with  old  age  or  by  accidental  factors  is  reUed  upon 
to  produce  seedbed  conditions  favorable  to  the  start  of  repro- 
duction. In  some  instances  cuttings  are  deferred  until  con- 
siderable reproduction  is  already  established  under  the  original 
over-mature  stand,  and  in  this  case  no  seed  cutting  is  required. 

Nature  then  frequently  accomplishes  the  purpose  of  the 
preparatory  and  seed  cuttings  and  enables  the  forester  to 
commence  his  work  with  the  removal  cuttings.  This  fact 
furnishes  one  of  the  reasons  why  the  shelterwood  method  may 
be  so  often  successfully  applied  in  an  extensive  manner. 
Opportunities  for  its  use  occur  principally  in  stands  of  virgin 
timber  which  are  opening  up  and  deteriorating. 

It  is  not  necessary  that  reproduction  be  already  on  the 
ground  when  the  first  cutting  is  made  or  that  the  best  condi- 
tions exist  for  the  start  of  reproduction,  although  this  latter 
is  desirable. 

The  first  cutting  will  have  for  its  purpose  the  partial  un- 
covering of  reproduction  already  estabHshed  and  the  estab- 
lishment of  reproduction  on  areas  not  yet  stocked.  While 
partaking  of  the  character  both  of  a  seed  cutting  and  a  re- 
moval cutting  it  may  be  termed  a  seed  cutting.  Forty  to 
75  per  cent  of  the  volume  is  taken  out.  The  trees  cut  are 
those  of  the  same  general  character  which  would  be  selected 
for  removal  in  the  preparatory  and  seed  cuttings  of  the 
method  when  applied  intensively. 

The  virgin  stands  in  which  extensive  application  most  fre- 
quently takes  place  usually  contain  a  large  percentage  of 
defective  trees.  Frequently  the  problem  in  the  first  cutting 
is  to  find  enough  trees  which  can  be  profitably  left  until  the 
next  cutting.  Good  health,  windfirmness,  capacity  for  seed 
production  and    favorable    location   with   respect    to  areas 


ADVANTAGES  AND   DISADVANTAGES  77 

which  require  restocking  or  groups  of  reproduction  which 
need  shelter,  together  with  the  length  of  time  before  the 
second  cut,  govern  the  selection  of  the  trees  to  be  retained. 
Ten  to  50  years  after  the  seed  cutting  a  second  one  called 
the  final  cutting  is  made,  taking  out  all  the  remaining  trees 
of  the  old  stand,  completing  the  reproduction  cuttings  and 
producing  an  evenaged  stand.  A  50  year  interval  between 
the  two  cuts  is  altogether  too  long  for  the  best  silvicultural 
results,  even  on  a  long  rotation  such  as  200  years.  Wherever 
market  and  logging  conditions  permit,  the  final  cutting  should 
follow  the  first  within  20  years. 

Advantages  and  Disadvantages  of  the  Method.  —  Advan- 
tages. —  I.  Heavy  seeded  species  whose  seeds  are  distributed 
principally  by  gravity  can  be  successfully  reproduced  as  well 
as  Hght  seeded  species.  Shelterwood  thus  stands  in  contrast 
to  the  clearcutting  and  seed  tree  methods  under  which  it  is 
difficult  if  not  impossible  to  secure  adequate  dissemination  of 
heavy  seeds. 

2.  Reproduction  is  more  complete  and  certain  than  under 
the  other  methods  of  high  forest  which  produce  evenaged 
stands  (clearcutting  and  seed  tree  methods).  This  is  because 
of  the  greater  number  of  seed  trees  which  are  present  during- 
the  time  reproduction  is  being  established  and  the  resulting 
larger  crops  of  seed  produced  and  available  on  all  parts  of  the 
area. 

3.  Shelterwood  is  only  exceeded  by  selection  in  its  protec- 
tive value.  The  ground  is  never  bare  of  a  forest  cover.  Even 
during  the  period  of  regeneration  the  old  stand  furnishes  pro- 
tection until  reproduction  is  fully  established  against  erosion, 
landslides,  snowslides  and  rapid  runoff  of  water.  Excessive 
growths  of  grass  and  herbaceous  cover  are  kept  in  check, 
while  seedlings  are  sheltered  from  the  drying  influence  of  sun 
and  wind  and  from  injury  by  frost.     Less  injury  from  insects 


78  THE   SHELTERWOOD   METHOD 

to  young  trees  may  be  anticipated  than  where  reproduction 
takes  place  on  clearings. 

4.  While  inferior  to  selection  in  the  maintenance  of  aesthetic 
effects  shelterwood  is  superior  to  all  other  high  forest  methods 
producing  evenaged  stands.  This  is  particularly  noticeable 
during  the  period  of  regeneration,  when  forests  treated  under 
the  clearcutting  and  seed  tree  methods  do  not  present  an 
attractive  appearance, 

5.  Since  shelterwood  is  the  only  high  forest  method  pro- 
ducing evenaged  stands  which  furnishes  shade  and  shelter  to 
seedlings,  it  is  the  best  method  to  use  with  species  which  can 
be  reproduced  naturally  only  under  such  conditions  and  for 
which  evenaged  stands  are  desired, 

6.  The  period  of  regeneration  in  each  stand  being  confined 
to  a  small  portion  of  the  rotation  permits  use  of  the  area  for 
grazing  during  the  remainder  of  the  rotation. 

Disadvantages.  - —  i.  Shelterwood  cannot  be  applied  when 
there  is  great  danger  from  windthvow  or  breakage  since  many 
trees  stand  isolated  during  the  regeneration  period.  The 
danger  may  be  minimized  by  several  preparatory  cuttings 
designed  to  develop  windfiryi  individuals  The  inherent  abil- 
ity of  the  species  to  withstand  windthrow  and  breakage  as 
well  as  the  relative  exposure  of  the  site  to  strong  winds  deter- 
mine the  importance  of  this  disadvantage.  With  a  species 
easily  injured  by  wind  or  on  much  exposed  sites  some  other 
method  besides  shelterwood  should  be  employed.  If  the 
method  can  be  applied  intensively  with  numerous  cuttings 
following  one  another  at  short  intervals  considerable  windfall 
need  not  interfere  with  its  successful  application.  The  dam- 
aged trees  are  salvaged  at  each  cutting.  Should  injury  by 
wind  affect  a  large  portion  of  the  old  stand  at  any  one  time 
the  results  might  be  serious. 

2,    Shelterwood  for  intensive  application  demands  economic 


APPLICATION   OF   SHELTERWOOD   METHOD  79 

conditions  making  profitable  the  removal  of  the  stand  in 
several  cuttings.     To  justify  such  operations  there  must  exist: 

A  market  for  small  sized  and  low  grade  forest  products 
(particularly  cord  wood). 

An  organization  of  the  logging  so  arranged  that  the  same 
area  can  be  operated  at  short  intervals  for  a  period  of 
years  necessary  to  establish  reproduction.  This  in- 
.  creases  the  expense  of  logging,  requiring,  as  it  does,  an 
extension  of  the  time  within  which  a  specific  amount  of 
timber  is  taken  from  a  given  area,  and  considerable 
care  to  preserve  reproduction  in  felling  and  transport- 
ing trees  from  the  felling  area. 

As  explained  under  ''Extensive  versus  Intensive  Applica- 
tion," page  76,  shelterwood,  shorn  of  its  refinements,  can  be 
used  in  a  crude  way  under  comparatively  poor  market  con- 
ditions. 

3.  Greater  technical  skill  is  called  for  in  applying  shelter- 
wood  than  is  needed  in  the  case  of  the  clearcutting  and  seed 
tree  methods.  When  selection  is  used  with  an  equal  degree 
of  intensiveness  it  calls  for  more  technical  skill  than  does 
shelterwood. 

4.  Part  of  the  reproduction  is  destroyed  in  the  removal 
cuttings.  Where  the  proper  care  is  exercised  the  inevitable 
destruction  of  some  young  trees  in  the  logging  will  not  reduce 
the  reproduction  below  the  point  of  full  density.  Careful 
work  to  keep  damage  to  reproduction  at  a  minimum  tends  to 
increase  the  expense  of  logging  as  previously  stated. 

Application  of  the  Shelterwood  Method.  —  As  yet  the  eco- 
nomic conditions  permitting  the  intensive  use  of  shelterwood 
are  found  in  relatively  few  sections  of  the  country.  East  of 
the  Great  Plains  and  north  of  Mason's  and  Dixon's  line  there 
are  many  districts  where    to-day  cordwood    is    salable  and 


8o  THE  SHELTERWOOD  METHOD 

logging  can  be  so  arranged  as  to  permit  shelterwood  cuttings. 
Numerous  instances  of  this  use  can  be  found  on  the  small 
tracts  typical  of  thickly  settled  districts. 

Many  of  the  heavy  seeded  hardwoods,  particularly  the  oak 
family,  are  species  which  can  be  best  managed  under  shelter- 
wood. 

Species  such  as  red  spruce,  eastern  balsam  and  eastern 
white  pine,*  which  under  certain  circumstances  desire  partial 
shade  and  protection  for  reproduction,  frequently  can  be 
successfully  handled  by  the  shelterwood  method. 

For  parks  and  estates  where  aesthetic  effects  are  desired 
along  with  production  of  timber  in  evenaged  stands  shelter- 
wood  should  be  chosen. 

Shelterwood  extensively  applied,  i.e.,  with  two  cuttings,  is 
suitable  for  all  evenaged  stands  where  the  individual  trees 
are  mainly  of  merchantable  size  and  condition  but  not  over- 
mature. Throughout  the  western  United  States,  where  in 
many  places  conservation  of  soil  moisture  and  protection 
from  sun  and  wind  is  essential  for  the  success  of  natural  re- 
production, a  crude  form  of  shelterwood  can  often  be  applied. 
The  pure  forests  of  western  yellow  pine  found  in  the  Black 
Hills  ^  of  South  Dakota  furnish  a  good  illustration.  Natural 
reproduction  in  this  region  starts  so  abundantly  under  a  par- 

*  An  illustration  can  be  drawn  from  a  permanent  sample  plot  established 
in  1905  in  a  53  year  old  white  pine  stand  at  Keene  growing  on  a  gravelly  sand  of 
second  quality. 

Two  cuttings  have  been  made,  a  light  one  (preparatory  cutting)  in  1900 
followed  by  a  heavy  one  (seed  cutting)  in  1904  which  left  the  crowns  of  the 
remaining  trees  a  few  feet  apart.  1904  was  a  heavy  seed  year.  At  the  time 
of  establishment  in  1905  over  11,000  white  pine  seedlings  per  acre  were  pres- 
ent nearly  all  from  the  1904  seed  crop.  In  1909  seedlings  up  to  18  inches  in 
height  to  the  number  of  4000  per  acre  still  persisted  under  the  shelter  of  the 
old  stand.  The  overwood  was  cut  clear  in  the  winter  of  1912-13.  In  1915 
there  was  an  average  stand  of  1500  white  pine  seedlings  per  acre  ranging  up  to 
four  feet  in  height.  The  stand  had  been  successfully  reproduced  by  the  shel- 
terwood method. 


REFERENCES  8l 

tial  (or  in  some  cases  under  a  complete  cover)  as  to  make  a 
two  cutting  shelterwood  method  successful. 

Many  western  yellow  pine  stands  elsewhere  in  the  west 
will  undoubtedly  be  treated  in  a  similar  manner.  The  prin- 
cipal difficulty  under  the  economic  conditions  existing  in  the 
western  yellow  pine  regions  is  to  make  the  second  and  final 
cutting  soon  enough  after  the  first  cutting  for  the  best  silvi- 
cultural  results  to  the  young  stand.  A  30  to  60  year  interval 
may  have  to  elapse  between  cuttings. 

As  a  general  thing  neither  the  economic  situation  nor  the 
silvicultural  condition  of  the  stand  justifies  an  intensive  appH- 
cation  of  shelterwood  in  stands  of  old  growth  timber.  In 
such  stands  reproduction  is  apt  to  be  present  in  greater  or  less 
amount  and  the  cuttings  may  be  begun  in  the  removal  cutting 
stage. 

Old  growth  timber  is  rarely  found  to-day  located  close  to 
good  markets  and  susceptible  of  intensive  treatment. 

Second  growth  stands  younger,  more  regular  and  made  up 
of  trees  of  smaller  size  than  the  virgin  timber,  offer  better 
opportunities  for  management  under  the  shelterwood  method. 

REFERENCES 

1.  Wagner,  C.  Grundlagen  der  Raumlichen  Ordnung  im  Walde.  Second 
edition,  Tubingen,  191 1. 

2.  Recknagel,  a.  B.  Border  Cuttings  —  A  Suggested  Departure  in 
American  Silviculture.  Proceedings  of  the  Society  of  American  Foresters, 
Vol.  VII,  1912,  pp.  145-152. 

3.  Smith,  P.  T.  A  Silvicultural  System  for  Western  Yellow  Pine  in  the 
Black  HQls.  Proceedings  of  the  Society  of  American  Foresters,  Vol.  X,  1915, 
pp.  294-300. 

Bericht  uber  den  Waldbaukurz  in  Langenbrand  im  September,  1913.  Forst- 
wissenschaftliches  Centralblatt,  Berlin,  1914,  pp.  87-97. 

Fisher,  R.  T.,  and  Terry,  E.  I.  The  Management  of  Second  Growth  White 
Pine  in  Central  New  England.  Journal  of  Forestry,  Vol.  18,  1920,  pp. 
358-363. 


82  THE   SHELTERWOOD   METHOD 

Frothingham,  E.  H.     White  Pine  under  Forest  Management.     Bulletin  13, 

United  States  Department  of  Agriculture,  Washington,  1914,  pp.  42-43. 
Mitchell,  J.  A.     Incense  Cedar.     Bulletin  604,  United  States  Department  of 

Agriculture,  Washington,  1918,  p.  34. 
Moore,  B.     The  Sihlwald,  an  Example.     American  Forestry,  Vol   17,  1911, 

PP-  531-536. 
Recknagel,  a.  B.     Some  Aspects  of  European  Forestry.     4.   Natural  Re- 
generation in  the  Black  Forest.     Forestry  Quarterly,  Vol.  11,  1913,  pp. 

330-339- 
Sieber-Ernsee,  Ph.     Ueber  Natiirliche  Verjiingung.     Forstwissenschaftliches 

Centralblatt,  1914,  pp.  181-195. 
Smythies,  E.  a.     Sylvicultural  Systems  of  Regeneration  in  Chir  Pine  Forests. 

The  Indian  Forester,  Vol.  39,  Dehra  Dun,  1913,  pp.  513-525. 
Sterrett,    W.    D.     The   Ashes :    Their    Characteristics    and   Management. 

Bulletin  299,  United  States  Department  of  Agriculture,  Washington,  1915, 

pp.  42-43- 
Troxip,  R.  S.     Pinus  Longifolia,  Roxb.     A  SyKucultural  Study.     The  Indian 

Forest  Memoirs,  Vol.  I,  Part  I,  Silviculture  Series,  Calcutta,  1916,  pp. 

81-99. 
WooLSEY,  T.  S.,  Jr.     Natural  Regeneration  of  French  Forests.     American 

Forestry,  Vol.  26,  1920,  pp.  77-81. 
WooLSEY,  T.   S.,  Jr.     Cutting  Western  Yellow  Pine  in  Arizona  and  New 

Mexico.     Proceedings  of  the  Society  of  American  Foresters,  Vol.  9,  1914, 

PP-  479-503- 


CHAPTER  VI 
THE   SELECTION  METHOD 

Definition.  —  According  to  the  principle  of  the  selection 
method  the  oldest  or  largest  trees  in  a  stand  are  chosen  for 
cutting,  and  the  remainder  are  left.  After  one  or  more  years 
another  cutting  of  the  same  character  is  made.  This  process 
is  repeated  at  intervals  throughout  the  rotation.  The  trees 
taken  in  a  single  cutting  may  occur  singly  or  in  small  groups. 
A  stand  is  never  completely  cleared  off,  but  instead  small 
openings  are  made  here  and  there.  After  each  cutting  re- 
production should  start  in  the  openings  just  created.  The 
necessary  seed  will  be  furnished  by  the  trees  standing  around 
the  openings. 

Form  of  Forest  Produced.  —  From  what  has  been  said  it 
is  evident  that  cuttings  under  the  selection  method  must 
produce  an  unevenaged  form  of  forest.  Such  form  is  not  a 
necessary  condition  for  starting  the  method.  Evenaged  stands 
ordinarily  contain  trees  of  considerable  range  in  diameter.  By 
selecting  at  each  cutting  the  largest  (if  not  the  oldest)  trees, 
an  evenaged  stand  may  be  reproduced  under  the  selection 
method  *  and  eventually  converted  into  unevenaged  form. 

A  stand  ideally  suited  to  a  selection  method  of  cutting 
should  contain  trees  of  every  age  class  from  one  year  seedhngs 
to  veterans  of  the  rotation  age.  Such  stands  are  not  found 
in  Nature,  but  are  most  nearly  approximated  in  virgin  forests. 

*  An  exception  to  this  statement  occurs  where  the  smaller  trees  in  an  even- 
aged  stand  lack  the  power  of  recovery  from  their  suppressed  condition,  or  are 
so  small  crowned  and  spindling  as  to  be  windthrown,  injured  by  sun-scald,  etc. 
83 


84  THE  SELECTION  METHOD 

But  in  virgin  forests  (ordinarily  considered  all-aged)  certain 
of  the  younger  or  middle  age  classes  are  lacking,  or  not  repre- 
sented in  the  right  proportion  and  the  stand  is  apt  to  be  com- 
posed either  of  mature  trees  of  about  the  same  height  and 
differing  comparatively  little  in  age  ^  or  else  to  be  of  the  two- 
storied  character,  each  story  being  of  practically  the  same 
age.  Since  it  is  virtually  impossible  in  Nature  to  find  all  age 
classes  represented  in  a  single  stand,  a  forest  is  considered  an 
all-aged  or  selection  forest  if  a  few  broad  age  classes,  each  of 
20  to  50  year  range,  are  represented. 

Details  of  the  Method. — In  theory  the  oldest  age  class  is  cut 
each  year,  the  next  oldest  removed  in  the  following  year,  and 
so  on  indefinitely.  Reproduction  springs  up  in  the  openings 
immediately  after  cutting.  By  the  time  all  the  age  classes  in 
an  all-aged  stand  have  been  cut  over  once  seedlings  started  on 
the  area  occupied  by  the  age  class  which  was  cut  first  will 
have  matured.  Thus  in  a  true  selection  stand  an  old  age 
class  ripe  for  cutting  will  be  available  each  year.  (See  Fig... 
25  and  Fig.  26.)  The  volume  of  this  age  class  will  be  equiva- 
lent to  the  annual  growth  of  the  stand.  Each  age  class  should 
occupy  its  proper  per  cent  of  the  area.  For  example,  if  there 
are  a  hundred  age  classes,  each  class  should  have  one  hun- 
dredth of  the  crown  space  allotted  to  it;  and  then  if  one 
hundredth  of  the  area,  in  this  instance,  is  each  year,  actually 
cleared  of  trees  or  uncovered,  only  the  trees  belonging  in  the 
oldest  age  class  will  be  removed.  Since  the  trees  making  up 
the  oldest  age  class  are  scattered  it  is  necessary  to  work  through 
the  whole  stand  to  find  them  and  to  conduct  logging  opera- 
tions over  the  whole  area  each  year. 

In  practice  certain  changes  in  this  theory  are  demanded 
both  from  the  logging  and  the  silvicultural  standpoints.  The 
annual  working  of  the  whole  area  to  secure  a  small  cut  per 
acre  makes  logging  relatively  expensive.     Seed  trees  do  not 


DETAILS   OF   THE   METHOD 


87 


produce  seed  every  year  and  seedlings  have  difficulty  in  becom- 
ing firmly  established  when  the  area  is  cut  over  each  year. 
To  avoid  these  difiiculties  what  is  known  as  a  cutting  cycle  is 


31      . 

^-^ 

52 

Y^'' 

1^  G6     A 

/    22 

^ 

/" 

18 
43 

/^     1    91 
^    7G    ^ 

^  \    47 
57      J         / 

74 

GO 
-i 

\    37 

"^ v/  12    ~ 

49X^88 

10  y-v'  / 

48      X 

8 

,3/ 

G2 

94 

(^ 

^. 

f    90 

^ 

N_X 

_^^'^^ 

~-( 100  \  5 

T  20 

ri 

. 

'1 

44       YV 

T^ 

i9    \^G3 

4,^^89   y 

75  jh 

"/ 

80 
"7— 

■ — ' 

83 

A    34       50  ( 

13 

'     93    S 

1  54 

2G 

K 

/g8 

58 

''Yv 

^ 

/     81     J 

^5/^5 

£^ 

s  33  ^ 

i — ' 

P^ 

30     ( 

^         (95 

G          V.        y^ 

40    ^ 
'    G7 

53  ^ 

^  27  y  \ 

98 

Vv 

87 

!■■! 

7 

25 

Fig.  27. 

A  portion  (one  acre)  of  an  ideal  single  tree  selection  stand,  managed  on  a 
rotation  of  100  years,  with  a  complete  series  of  age  classes  on  every  acre,  each 
occupying  approximately  the  same  area.  The  numbers  indicate  the  ages  of  the 
trees  occupying  given  portions  of  the  acre. 

established.  Under  this  scheme  the  entire  forest  is  not  cut 
over  each  year;  but  it  is  divided  into  certain  distinct  stands. 
The  cutting  in  a  given  year  is  restricted  to  one  of  these  areas. 


88 


THE  SELECTION  METHOD 


Cuttings  in  successive  years  progress  from  one  stand  to  an- 
other and  finally  return  to  the  first.  The  interval  between  cuts 
on  a  given  area  determines  the  length  of  the  cutting  cycle. 


20 

1   ^ 

90 

\    50 

1     20 

/i      90 

\-^f 

^.0 

30 

/    60 

/ 

I 

80 

"^    40 

^      30^ 

T 

10     ^ 

\  A 

70      yr/ 

90      ( 

50 

90 

80 

^   10 

60 

~^ 

li" 

1    GO 

\   70 

j\y 

> — s 

r 

^ 

-^ 

—^ 

t — 

^      ^ 

\  -o\ 

80 

f     50  y 

y  J 

60    / 

40 

/ 

30 

70 

P 

<x     80 

\    30    "^^ 

70     1 

wo 

/ 

/    90 

S  10 

JV 

2^ 

'    70 

b 

J     - 

J—/   CO 

\     21 

^  50 

(    y 

^/f 

100    A 

H 

LOO        1 

jTjl    100    [   \^ 

'"x/ 

'  80  / 

20 

J- 

■v-^ 

40  y^ 

N^ 

~-j . 

30 

rA    10 

80 

1      50 

}    60 

i     10    J 

80 

1       60 

j    50 

/lOO 

60      i 

40  Y 

50 
^90 

A    30 

/     90 

fi 

100 

r 

)    20 

t 

^ 

r' 

100   i 
10     ' 

20    ( 
k        / 
^.0 

30 

/  100 

80^ 

y  70 

?J 

ri 

GO 

50 

rv 

'  so 

30 

1    100 

»t 

Fig.  28. 
A  portion  (one  acre)  of  an  ideal  single  tree  selection  stand  managed  on  a 
rotation  of  100  years  under  a  10  year  cutting  cycle.  Ten  age  classes  are  rep- 
resented each  occupying  approximately  one-tenth  of  the  area.  The  numbers 
indicate  the  age  of  the  trees.  Compare  with  Fig.  27,  where  a  cutting  cycle 
of  one  year  is  employed. 

In  Europe  this  is  apt  to  be  10  years  or  lower.  In  the  United 
States  the  cutting  cycle  may  be  10  to  50  years  in  length. 
Where  the  cutting  cycle  is  longer  than  one  year  every  age 


DETAILS   OF   THE   METHOD 


89 


will  not  be  represented  in  the  stand.  There  will  be  as  many 
ages  in  the  stand  as  there  are  cuttings  during  the  rotation. 
To  secure  this  number  divide  the  rotation  by  the  cutting 
cycle.     (See  Figs.  27,  28  and  29.) 


Stand  1 

Stand  2 

Stand  3 

Stand  4 

Stand  5 

Contains 
age  classes:- 

Contains 
age  classes:- 

Contains 
age  classes:- 

Contains 
age  classes: - 

Contains 
age  classes:- 

1,   11,  21, 

2,  12,  22, 

3,  13,  23, 

4,  14,  24, 

5,  15,  25, 

31,   41,  51, 

32,  42,  52, 

33,  43,  53, 

34,  44,  54, 

35,  45,  55, 

61,  71,  81, 

62,  72,  82, 

63,  73,  83, 

64,  74,  84, 

65,  75,  85, 

and  91 

and  92 

and  93 

and  94 

and  95 

Stand  6 

Stand  7 

Stand  8 

Stand  9 

Stand  10 

Contains 
age  classes:- 

Contains 
age  classes:- 

Contains 
age  classes:- 

Contains 
age  classes :- 

Contains 
age  classes:- 

6,  16,  26, 

7,  17,  27, 

8,  18.  28, 

9,  19,  29, 

10,  20,  30, 

36,  46,  56, 

37,  47,  57, 

38,  48,  58, 

39,  49,  59, 

40,  50,  60, 

66,  76,  86, 

67,  77,  87, 

68,   78,  88, 

69,  79,  89, 

70,  80,  90, 

and  96 

and  97 

and  98 

and  99 

and  100 

Fig.  29. 
Diagram  of  a  selection  forest  managed  on  a  rotation  of  loo  years  with  a  cut- 
ting cycle  of  10  years.  The  forest  contains  lo  stands,  one  of  which  is  cut 
through  each  year,  thus  giving  equal  annual  cuts.  Each  stand  contains  lo 
age  classes  and  together  the  age  classes  in  the  lo  stands  form  a  continuous 
series  of  ages  from  i  to  100  years. 

As  the  interval  between  cuts  is  lengthened  the   amount 
per  acre  removed  in  a  single  cutting  is  increased  in  direct 


90  THE   SELECTION   IMETHOD 

proportion  to  the  increased  length  of  the  cycle.  For  example, 
if  200  board  feet  per  acre  are  removed  when  a  given  stand  is 
cut  through  annually,  then  10  X  200  =  2000  board  feet  per 
acre  should  be  removed  at  each  cutting  if  the  cutting  cycle  is 
changed  to  10  years.  If  the  amount  to  be  cut  on  an  annual 
cutting  cycle  is  known,  then  the  cut  for  any  other  cycle  can 
be  quickly  secured  by  multiplying  the  length  of  cycle  by  the 
annual  cut  per  acre. 

The  actual  percentage  of  the  volume  removed  in  a  selection 
cutting  is  subject  to  great  variation  depending  on  the  length 
of  the  cutting  cycle  and  the  unit  in  which  the  volume  is 
expressed.  When  the  board  feet  unit  is  employed  100  per  cent 
of  the  volume  might  be  removed  in  a  given  cutting  provided 
the  old  age  class  included  all  the  trees  of  merchantable  dimen- 
sions. More  commonly  on  a  cutting  cycle  of  10  to  20  years, 
25  to  75  per  cent  of  the  board  foot  volume  would  be  cut. 
Expressed  in  tenns  of  cubic  feet  the  percentage  would  usually 
range  from  15  to  50  per  cent. 

This  leads  to  the  question  as  to  how  the  amount  per  acre 
which  can  be  cut  should  be  determined.  If  all  age  classes  are 
represented  each  occupying  the  proper  proportion  of  the 
area  it  is  easy  to  limit  the  cut.  Either  the  annual  growth  or 
the  oldest  age  class  could  be  removed  each  year,  or  the  peri- 
odic growth  be  removed  at  the  end  of  each  cutting  cycle, 
and  sustained  annual  yield  in  an  unevenaged  stand  be  main- 
tained indefinitely.  The  two  {i.e.,  annual  growth  or  oldest 
age  class)  are  identical  in  volume  provided  the  proper  pro- 
portion exists  between  age  classes.  Unfortunately  this  ideal 
stand  is  non-existent  which  makes  more  complicated  the 
problem  of  determining  the  amount  to  cut.  The  following 
procedure  is  suggested.* 

*  This  question  of  limiting  the  cut  or  regulating  the  yield  from  a  given  area 
falls  under  regulation  and  outside  the  province  of  silviculture."     Yet  under  the 


DETAILS   OF   THE   METHOD  91 

1.  Decide  on  the  length  of  rotation.  This  has  influence  on 
the  possible  growth  and  on  the  number  of  age  classes  which 
should  be  represented. 

2.  Determine  the  mean  annual  growth  per  acre.* 

3.  Ascertain  the  proportion  of  the  area  occupied  by  each 
age  class.* 

4.  If  each  age  class  occupies  its  right  proportion  of  the 
area  the  annual  cut  is  equal  to  the  mean  annual  growth. 

5.  If  the  age  classes  are  not  represented  in  the  right  pro- 
portion decide  what  relation  the  amount  cut  for  the  next 
few  years  or  for  the  next  cutting  cycle  shall  bear  to  the  mean 
annual  growth. 

6.  The  amount  to  be  cut  having  been  determined  select 
enough  trees  to  give  this  amount  from  the  older  age  classes 
on  the  basis  of  their  silvicultural  condition,  considering  par- 
ticularly such  points  as  individual  health,  rate  of  growth  and 
seed-bearing  value.  On  the  whole  the  oldest  trees  would  be 
removed  but  opportunity  is  afiforded  for  taking  out  poor 
individuals  of  younger  age,  and  of  leaving  certain  thrifty 
trees  of  older  age. 

The  age  of  standing  mature  trees  cannot  be  secured  directly 
without  cutting  or  boring  into  them.  As  this  is  unpracticable 
diameter  is  taken  as  the  best  indication  of  age  and  the  trees 

selection  method  success  in  maintaining  its  typical  form  of  forest  is  associated 
so  much  more  intimately  with  proper  regulation  than  in  the  case  of  methods 
producing  evenaged  stands,  that  brief  mention  is  warranted.  In  fact  regulation 
either  on  an  annual  or  relatively  short  period  basis  is  essential  to  silvicultural 
success  under  the  selection  method. 

*  It  is  recognized  that  determining  for  an  unevenaged  stand,  either  the 
mean  annual  growth  per  acre,  or  the  proportion  of  the  area  occupied  by  indi- 
vidual age  classes  is  a  mensuration  problem  as  yet  without  completely  satis- 
factory solution.  However,  both  problems  can  be  answered  within  Umits  of 
accuracy  which  should  furnish  sufficient  control  for  governing  the  cut.  An 
attempt  to  elaborate  methods  of  attacking  these  mensuration  problems  is 
considered  out  of  place  here. 


92 


THE  SELECTION  METHOD 


assigned  to  age  classes  on  the  basis  of  size.  For  this  purpose 
tables  showing  the  average  age  of  trees  of  different  diameters 
can  be  made  by  analysis  of  the  growth  of  felled  trees. 

A  diameter  limit  may  then  be  established  with  the  under- 
standing that  trees  below  this  size  are  to  be  reserved  and 
those  above  cut.  This  should  not  be  made  a  rigid  limit  but 
should  be  apphed  discriminatingly,  certain  trees  above  the 
limit  being  reserved  and  some  below  the  limit  cut.  In  the 
parallel  columns  given  below  the  chief  reasons  for  cutting 
below  or  leaving  trees  above  the  Umit  are  summarized. 

Trees  may  be  left  above  the  diameter      Trees  may  be  cut  below  the  diameter 


limit  when: 
I.  Exceedingly  thrifty  and  growing 
fast  in  volume  and  in  value. 


2.  Standing  in  groups  of  smaller 
trees  and  liable  if  cut  to  cause 
windthrow  or  breakage  among 
these  trees.     (See  Fig.  30.) 


3.  A  large  seed  tree  is  needed  in  or 

on  the  edge   of  an  opening. 
(See  Fig.  31.) 

4.  Needed  for  aesthetic  reasons. 

5.  Required  to  protect  soil  condi- 

tions or  seedlings. 


Umit  when: 

Unthrifty,  slow  growing  and 
likely  to  decay  or  be  killed  be- 
fore another  cutting  and  those 
at  present  defective. 

So  exposed  that  if  left  they  will 
be  windthrown  or  broken  in 
feUing  neighboring  trees.  This 
is  apt  to  occur  in  case  of  tall, 
slender  individuals  growing  in 
a  group  of  larger  trees. 

By  so  doing  the  composition  may 
be  improved  or  the  rate  of 
growth  of  more  promising 
neighbors  increased.  (See 
chapters  on  Intermediate  Cut- 
tings.) 


The  great  temptation  in  cutting  timber  under  the  selection 
method  is  to  take  too  much;  in  other  words  to  cut  trees  too 
young  or  too  small  and  thus  deplete  the  younger  and  middle 
age  classes. 

This  temptation  exists  because  the  young  trees  are  inter- 
mingled with  the  old  age  classes  instead  of  being  segregated 
on  separate  areas  as  in  the  other  high  forest  methods.  Even 
though  the  merchantable  trees  below  the  diameter  limit  are 


^98J  08- 


94 


DETAILS   OF   THE   METHOD  95 

not  cut  many  of  the  smaller  trees  may  be  used  in  the  logging 
operations,  for  skids,  corduroying  roads,  etc.,  or  simply  de- 
stroyed in  felling  and  getting  out  the  timber.  A  certain 
amount  of  destruction  is  a  necessary  accompaniment  to  log- 
ging, but  such  wasteful  use  and  destruction  may  be  so  extreme 
as  to  threaten  the  continued  existence  of  the  selection  forest. 
In  order  to  provide  for  enough  old  trees  per  acre  it  is  necessary 
that  numerous  seedlings  start  every  few  years.  These  seed- 
lings undergo  a  rapid  decrease  in  numbers  due  to  competition 
and  other  natural  causes  as  they  grow  in  size  and  advance 
toward  maturity.  Definite  information  as  to  the  number  of 
trees  per  acre  of  different  sizes  needed  to  secure  steady  pro- 
duction under  the  selection  method  is  not  available  for  most 
of  our  species.  As  an  illustration  the  following  data  for  yel- 
low poplar  have  been  taken  from  "Yellow  Poplar  in  Tennes- 
see," by  W.  W.  Ashe.^  See  also  pp.  317-318  in  the  Selection 
System  in  Indian  Forests  .  .  .  ,  by  Caccia.^ 

Number  of  trees  per  acre  in  different  diameter  classes,  required  to  obtain  a 
continuous  yield  from  a  fully  stocked  group  selection  stand  of  pure  yellow- 
poplar.     The  cutting  limit  is  approximately   20  inches. 

Diameter,  Number  of  trees 

Breast  High,  per  acre  on  average 

Inches  quahty  sites 

2-4 280 

5-  8 151 

9-12 57 

13-16 19 

17-20 5 

Above  20 I 

Total '.'.[^'.'.'.'.\'.'.'.'.'.  JTs 

If  to  these  natural  causes  are  added  destruction  by  the 
lumberman,  there  may  be  no  representatives  left  of  certain 
ages  to  come  to  maturity.  It  is  essential  for  successful  appli- 
cation of  the  selection  method  that  waste  of  small  trees  be 
kept  at  the  minimum. 


96  THE  SELECTION  METHOD 

Graves  described  a  method  of  limiting  the  cut^  which  has 
been  used  to  some  extent  in  the  United  States  Forest  Service 
reports  and  elsewhere.  Under  this  method  different  diam- 
eter limits  of  cutting  are  assumed,  the  number  of  trees  of 
each  diameter  and  the  present  yield  of  timber  cutting  to  the 
limit  calculated,  and  then  by  means  of  current  diameter 
growth  data  the  dimension  and  volume  of  the  trees  left 
standing  below  the  limit  are  estimated  at  the  end  of  a  stated 
period,  such  as  30  years.  In  speaking  of  the  method  Graves 
says  "a  Hmitation  of  cut,  based  on  this  method  of  study, 
maintains  the  rate  of  growth  of  the  forest  and  guarantees 
succeeding  cuts  at  short  intervals."  Since  all  the  calcula- 
tions are  based  on  current  growth  for  a  relatively  short 
period  without  consideration  of  the  proper  distribution  of 
the  entire  series  of  age  classes,  the  method  does  not  guarantee 
cuts  at  short  intervals  except  the  one  immediately  following 
the  present  cut. 

Modifications  of  the  Selection  Method.  —  Group  Selection.  — 
In  defining  the  selection  method  it  was  stated  that  the  trees 
cut  at  any  one  time  might  be  standing  singly  or  in  small  groups. 
(See  Fig.  32.)  There  are  certain  advantages  in  maintaining  a 
group-wise  arrangement  of  the  trees  of  the  same  age.  Less 
breakage  among  younger  trees  is  caused  in  felling  and  remov- 
ing the  oldest  age  class.  The  cost  of  logging  may  be  slightly 
reduced.  More  light  is  provided  for  the  development  of  seed- 
lings and  young  trees.  This  is  of  especial  importance  in  the 
case  of  light  demanding  species.  Trees  intolerant  of  shade 
cannot  be  managed  under  a  method  of  single  tree  selection. 

By  varying  the  size  of  the  group  great  flexibility  in  applica- 
tion is  possible.  The  oldest  groups  may  contain  only  two  to 
five  trees  and  from  this  range  up  to  more  than  a  hundred 
occupying  one  to  four  acres.  Where  the  groups  occupy  more 
than  a  quarter  of  an  acre  the  stand  tends  to  lose  its  uneven- 


MODIFICATIONS   OF  THE  METHOD 


97 


aged  form.     With  larger  groups  one  of  the  distinctive  char- 
acteristics of  the  selection  method  is  lost,  namely  the  protec- 


\ 

80  years 

J       40  years 

-^'x.   60  years 

V 

] — ^ 

90  years     / 

o 

10  years    1 

100  years   / 
^ ^     y   20  years 

( 

30  years 

. 

50  years      j  / — 

Fig.  32. 

A  portion  (one  acre)  of  a  stand  reproduced  by  the  group  selection  method. 
Small  groups  are  shown  in  the  illustration  averaging  one-tenth  of  an  acre  in  size. 
Length  of  rotation  is  loo  years;  length  of  cutting  cycle  lo  years.  Compare 
with  Figs.  27  and  28.  Ten  age  classes  are  represented  in  this  stand  each  group 
containing  a  different  number  of  trees  depending  upon  its  age.  The  numbers 
indicate  the  age  of  the  trees  in  each  group. 

tion  of  the  site  and  of   seedhngs  so  essential  for  successful 
natural  reproduction.     The  groups  must  be  small  enough,  so 


98  THE   SELECTION  METHOD 

that  seed  can  be  distributed  in  abundance  over  the  cleared 
area,  and  so  that  surrounding  trees  may  conserve  soil  moisture 
and  shelter  reproduction.     (See  Figs,  t,^,  34  and  35.) 

With  increase  in  area  the  groups  tend  to  develop  like  small 
evenaged  stands  and  produce  trees  which  have  the  character- 
istics of  such  stands,  rather  than  of  trees  grown  in  an  uneven- 
aged  forest. 

Strip  Selection.  —  In  the  group  method  the  groups  of  trees 
of  the  same  age  have  the  general  outline  of  circles,  squares  or 
relatively  broad  rectangles.  Several  groups  of  the  same  age 
may  be  found  in  the  same  stand.  The  strip  selection  method 
carries  further  the  idea  of  the  groups.  All  the  groups  of  the 
same  age  in  a  stand  are  combined  in  the  form  of  a  long  nar- 
row strip.  There  will  be  at  least  as  many  of  these  strips  as 
there  are  age  classes  in  the  stand,  and  in  stands  of  large  areas 
several  strips  of  the  same  age  may  be  found.  (See  Figs.  36 
and  37.) 

Such  an  arrangement  concentrates  the  logging  and  results 
in  little  if  any  destruction  among  the  younger  trees.  The 
strips  should  be  made  so  narrow  that  good  soil  conditions  are 
preserved  and  reproduction  sheltered  by  the  bordering  uncut 
timber.  Each  strip  is  itself  of  even  age,  and  under  intensive 
management  might  be  considered  a  separate  stand,  in  which 
case  the  method  becomes  clearcutting  with  natural  repro- 
duction from  the  side. 

The  strip  selection  method  is  theoretical  in  the  extreme  and 
one  not  likely  to  be  developed  in  practice. 

Extensive  versus  Intensive  Application  of  the  Selection  Method. 
—  When  markets  are  poor  and  logging  expensive,  only  the 
biggest  and  best  trees  are  profitable  to  cut.  Under  these  cir- 
cumstances the  selection  method  can  be  applied  only  in  a 
crude  way  and  is  simple  in  its  operation.  Extensive  applica- 
tion means  long  intervals  between  the  cuts,  no  intermediate 


lOO  THE  SELECTION  METHOD 

cuttings,  growth  retarded  due  to  shade  and  a  relatively  small 
increment  of  valuable  material. 


Fig.  35. 

A  40-acre  portion  of  a  stand  of  virgin  timber  to  be  reproduced  under  the 
group  selection  method.  Four  groups  are  represented  in  the  diagram.  ^  Length 
of  rotation  is  200  years;  length  of  cutting  cycle  50  years.  The  oldest  group  is 
cut  clear  except  for  a  few  trees  shown  in  the  diagram  left  to  furnish  seed  over 
the  central  part  of  the  area.  Such  seed  trees  are  needed  because  the  group  is 
too  broad  to  be  adequately  reproduced  from  seed  distributed  from  trees  in 
adjoining  groups.  The  principal  difference  between  this  operation  and  the 
method  of  clearcutting  the  whole  stand  lies  in  the  difference  in  size  of  the  unit 
of  management  (i.e.,  the  stand).     See  page  13. 


nrsraT  nos,                                                                                    ,  1 

•< 

C5 
CO 

I 

CQ 

O 

(M 

it 

Q 

o 

-o 

a; 

LU 

©q 

ti 

o 

g 

i 

^ 

1 

O 

CM 
CI 

1 

X 

o 
o 

ft 

- 

-J 

a 

—-^^^-^ 

--Nv...--—              ^ 

w. 

.9 

a 


a  IS 


-a  -c 


If  economic  conditions 
allow  the  utilization  of  trees 
of  all  sizes  and  kinds,  then 
intensive  application  of  the 
selection  method  becomes 
possible.  This  implies 
short  intervals  between 
cuts,  proper  silvical  atten- 
tion to  each  tree  or  group, 
the  making  of  intermediate 
cuttings,  the  artificial  re- 
generation of  failed  places, 
if  such  exist,  and  a  relatively 
high  increment  of  valuable 
material. 

Advantages  and  Disad- 
vantages of  the  Selection 
Method.  — ■  The  selection 
method  with  its  uneven- 
aged  form  of  forest  stands 
in  sharp  contrast  to  the 
other  three  previously  con- 
sidered. For  this  reason 
it  is  to  be  expected  that 
definite  arguments  in  favor 
of  and  against  the  method 
can  be  presented. 

Advantages. —  i .  Affords 
a  high  degree  of  protection 
to  the  site  and  to  repro- 
duction and  minimizes  the 
danger  of  snow-slides  and 
land-slides.      The  forest 


ADVANTAGES   AND    DISADVANTAGES  103 

canopy  is  kept  nearly  complete,  the  openings  made  being 
small  and  scattered.  No  other  method  affords  such  perfect 
protection  against  erosion,  injury  to  the  physical  factors  of  the 
site  and  against  the  development  of  a  grass  and  weed  cover. 
Seedlings  receive  shelter  from  sun,  wind  and  early  and  late 
frosts.  The  continuous  cover  of  trees  of  all  ages  presents  a 
strong  mechanical  barrier  to  the  progress  of  land-  and  snow- 
slides.     Such  slides  rarely,  if  ever,  start  in  a  selection  forest. 

2.  Can  be  applied  extensively  where  markets  are  poor  and 
only  trees  of  large  size  are  merchantable.  Poor  market  condi- 
tions hamper  the  full  development  of  the  selection  idea,  but 
do  not  prevent  the  partial  use  of  the  method,  for  even  with 
the  poorest  markets  it  is  the  largest  trees  that  are  salable. 

3.  The  method  best  satisfies  the  aesthetic  purpose,  due  to 
its  picturesque  unevenaged  form,  and  avoidance  of  anything 
approaching  clean  cutting. 

4.  Windfall  is  eliminated  or  reduced  to  a  small  figure  in 
selection  forests.  The  individual  trees  have  the  opportunity 
to  develop  large  crowns,  compared  to  trees  in  evenaged  stands, 
and  become  windfirm.  The  small  trees  are  well  sheltered  by 
the  older  ones. 

5.  Reproduction  is  relatively  easy  to  secure,  due  to  an 
abundance  of  seed  trees  and  to  the  protection  afforded  the 
seedbed  and  seedlings. 

6.  The  selection  method  is  the  only  one  which  maintains 
the  unevenaged  form  of  forest. 

7.  There  is  less  danger  of  a  disastrous  fire  than  in  forests 
of  evenaged  stands  in  which  the  sohd  blocks  of  reproduction 
create  enormous  fire  hazard.  In  case  fire  does  occur  seed 
trees  are  always  present  to  stock  up  the  burned  area. 

8.  An  ideal  method  for  the  small  farm  woodlot,  because  it 
permits  annual  or  frequent  harvesting  of  large  timber.  Such 
a  woodlot  (of  five  acres  for  example)  is  too  small  to  be  effec- 


I04  THE   SELECTION  METHOD 

lively  organized  for  annual  or  short  period  yield  on  a  clear- 
cutting  or  shelterwood  method. 

Disadvantages.  —  i .  Since  the  mature  trees  are  scattered 
throughout  the.  whole  stand  and  are  intermixed  with  repro- 
duction and  small  trees  logging  costs  more  than  under  other 
methods. 

2.  Due  to  the  mixture  of  age  classes,  it  is  difficult  to  pre- 
vent in  the  logging  injury  to  the  immature  trees  which  form 
the  forest  capital. 

3.  Grazing  cannot  be  permitted  since  reproduction  is  m 
progress  continually. 

4.  The  timber  produced  averages  lower  in  grade  than  that 
grown  in  evenaged  stands.  It  is  more  apt  to  be  knotty  due 
to  the  greater  crown  development  of  the  individual  tree.  To 
some  extent  the  site  on  which  the  selection  method  is  ordi- 
narily employed  accounts  for  this.  Selection  forest  has  been 
used  principally  on  poor  sites  in  exposed  positions  and  at 
high  elevations  as  a  protective  forest.  On  such  situations 
the  timber  produced  under  any  method  is  of  lower  quality 
than  that  produced  on  better  sites. 

5.  To  apply  intensively  requires  great  skill  on  the  part  of 
the  forester.  This  results  from  the  complex  nature  of  the 
age  distribution  in  the  stand. 

Whether  the  method  gives  a  lower  increment  than  other 
methods  of  high  forest  has  been  a  point  of  controversy  abroad 
for  many  years.  Some  authors  contend  that  the  greater  area 
of  foliage  per  tree  and  the  more  complete  use  of  available 
nutrients,  resulting  from  the  mixing  of  young  and  old  trees 
with  root-systems  penetrating  to  different  depths,  must  work 
for  greater  production  under  the  selection  method.  The  argu- 
ment against  this  is  that  the  retardation  of  the  growth  of 
young  and  middle-aged  trees,  through  shading  by  older  ones, 
more  than  offsets  these  items.     It  is  not  until  the  last  half  of 


ADVANTAGES   AND   DISADVANTAGES 


105 


the  rotation  that  trees  in  a  selection  stand  are  completely 
freed  from  shading  by  taller  trees.  Analyses  of  the  growth  of 
individual  trees  show  marked  contrasts  between  those  grown 
in  evenaged  and  unevenaged  stands.^     (See  Figs.  38  and  39.) 


;S20 

.9 

m 

216 


gl2 

p 

a, 

as 


/ 

' 

/ 

/ 

,-> 

^,- 

--"' 

x' 

7 

-»,  .^' 

' 

j 

/ 

^f 

/ 

/ 

/ 

V 

/ 

/ 
/ 

<< 

/ 

1 

1 

/ 

^ 

1 
1 

/ 

/ 

/ 

/ 

/ 

/ 

^^ 

/ 
/ 

^ 

0 


20 


40 


100 


120 


140 


60  80 

Age  in  Years 
Fig.  38. 

Diagrams  showing  the  diameter  growth  based  on  age  of  two  hemlock  trees 
of  approximately  the  same  age  and  size  growing  on  the  same  site.  Tree  A 
grew  under  conditions  prevailing  in  an  unevenaged  stand.  Tree  B  grew  under 
conditions  prevailing  in  an  evenaged  stand.  For  the  first  50-60  years  of  its 
life  tree  A  was  overtopped. 

Much  of  the  difference  in  opinion  as  to  the  relative  pro- 
duction of  evenaged  and  unevenaged  stands  arises  from  unfair 


io6 


THE    SELECTION   METHOD 


comparisons  between  the  two.  To  gauge  the  relative  pro- 
duction of  two  methods  the  same  intensity  of  appKcation  must 
be  employed  in  the  management  and  the  two  stands  must  be 
on  the  same  quality  of  site.     When  these  conditions  are  met 

60 


^ 

r^' 

/' 

! 

.-■ 

.'-'■ 

7 

i 

.^. 

r''' 

/ 

,.^^ 

..-^' 

A 

V 

/ 

J 

'/ 

/ 

/ 

/ 

/ 

y 

/ 
/ 
/ 

y 

y 

/ 

' } 

y^ 

/> 

/- 

40  60  80  100 

Age  in  Years 

Fig.  39. 


140 


Diagrams  showing  the  height  growth  based  on  age  of  the  two  hemlock  trees 
used  in  Fig.  38.  Tree  A  grew  under  conditions  prevaihng  in  an  unevenaged 
stand;  tree  B  under  those  prevaihng  in  an  evenaged  stand. 

the  production  of  evenaged  and  unevenaged  stands  should  be 
equal. 

Application  of  the  Selection  Method.  —  In  European  coun- 
tries the  selection  method  finds  favor  principally  for  use  on 
sites  where  a  protection  forest  is  needed.  Switzerland  has 
a  higher  percentage  of  protection  forests  than  have  other 


APPLICATION   OF  THE   SELECTION   METHOD  107 

countries.  Her  statistics  indicate  that  35  per  cent  of  the 
total  forest  area  and  two-thirds  of  the  forest  in  the  Alpine 
district  are  handled  under  the  selection  method. 

In  the  United  States  so-called  "selection"  cuttings  have 
been  made  in  various  regions  and  types.  In  many  cases  the 
name  is  a  misnomer,  the  character  of  the  cutting  indicating 
plainer  than  words  that  the  selection  method  is  not  being 
employed.  Where  true  selection  cuttings  have  been  made, 
they  are  principally  in  mixed  stands,  where  large  sized  trees 
of  only  one  or  a  few  species  were  merchantable.  Where 
market  conditions  have  improved,  making  more  species  and 
smaller  sizes  salable,  the  second  cutting  made  in  such  stands 
does  not  have  the  character  of  a  selection  cutting. 

Overmaturity  of  timber  and  too  great  a  preponderance  of 
the  older  age  classes  present  great  difficulties  to  the  immedi- 
ate use  of  selection  in  many  forests,  where  eventually  it  may 
be  the  most  desirable  method. 

As  explained  on  page  84,  the  virgin  forest  contains  an  excess 
of  the  older  age  classes.  When  to  this  condition  is  added  the 
fact,  that  the  rotation  under  management  will  be  much  shorter 
than  the  normal  Ufe  of  a  tree  in  the  virgin  forest,  this  excess 
of  old  timber  becomes  more  pronounced. 

For  example  a  certain  virgin  forest  contains  age  classes 
ranging  from  young  seedlings  to  trees  500  years  of  age,  with 
merchantable  timber  from  100  to  500  years  occupying  at  least 
90  per  cent  of  the  area.  Theoretically  these  age  classes 
should  cover  80  per  cent,  so  that  the  age  class  distribution 
may  appear  nearly  correct.  Under  management  the  rota- 
tion for  this  forest  wiU  be  set  at  100  years.  This  being  the 
case,  90  per  cent  of  the  forest  area  is  stocked  at  present  with 
overmature  timber  past  the  rotation  age.  A  clearcutting  is 
apt  to  be  the  only  solution.     Selection  is  out  of  the  question. 

For  sites  in  great  need  of  protection,  selection  is  recognized 


Io8  THE   SELECTION  METHOD 

as  the  proper  method  and  is  already  being  applied  on  a  small 
scale. 

Besides  its  general  employment  on  protection  sites,  which 
will  come  in  time,  the  selection  method  should  be  favored  by 
farmers  holding  small  areas  of  woodland  and  by  owners  with 
whom  the  aesthetic  motive  is  prominent.  This  latter  class  is 
increasing,  and  already  holds  large  areas  in  the  aggregate. 

There  may  also  be  occasional  examples  where  the  influence 
of  economic  conditions  and  the  silvical  habits  of  the  species 
point  to  the  adoption  of  the  selection  method  for  the  produc- 
tion of  timber  on  a  large  scale.  An  instance  of  this  character 
is  furnished  by  lodgepole  pine  in  the  Rocky  Mountains. 

Lodgepole  grows  on  sites  which  are  often  spoken  of  as 
protection  sites,  but  yet  are  sites  which  from  their  location 
topographically  are  not  in  most  instances  the  real  protection 
sites  of  the  locality.  These  are  found  in  timbered  areas 
located  above  the  lodgepole  type.  Stated  in  another  way,  a 
great  share  of  the  lodgepole  pine  type  may  be  used  primarily 
to  grow  timber  without  interfering  with  its  protective  value. 
This  situation  would  permit  theoretically  the  use  of  shelter- 
wood  or  clearcutting  rather  than  selection.  The  United 
States  Forest  Service  after  trying  various  forms  of  clearcut- 
ting and  the  seed  tree  methods  have  swung  around  to  selection 
as  best  meeting  the  market  requirements  of  the  region  and 
fitting  in  with  the  silvical  habits  of  lodgepole  pine.^  Certain 
forms  of  stand  demand  immediate  reproduction  under  other 
methods,  but  the  indications  are  that  for  lodgepole  pine 
selection  will  be  on  the  whole  the  best  method  of  reproduc- 
tion and  the  unevenaged  forest  the  most  desirable  form. 


REFERENCES  109 


REFERENCES 

1.  Cermak,  Einiges  iiber  den  Urwald  von  WaldbauKchen  Gesichtspunkten. 
Centralblatt  f.  d.  g.  Forstwesen,  Aug.-Sept.,  1910,  pp.  340-370. 

2.  Ashe,  W.  W.  Yellow  Poplar  in  Tennessee.  Bulletin  lo-C,  State  of 
Tennessee,  State  Geological  Survey,  1913,  p.  40. 

3.  Caccia,  a.  M.  F.  The  Selection  System  in  Indian  forests  as  exempli- 
fied in  working  plans  based  on  this  system,  with  a  short  description  of  some 
Continental  Methods.  The  Indian  Forest  Records,  Part  IV,  Vol.  I,  Calcutta, 
1909,  p.  315,  317-318. 

4.  Graves,  H.  S.  Principles  of  Handling  Woodlands.  Wiley  &  Sons,  Inc., 
New  York,  1911^  pp.  53-54. 

5.  Mason,  D.  T.  Utihzation  and  Management  of  Lodgepole  Pine  in  the 
Rocky  Mountains.  Bulletin  234,  United  States  Department  of  Agriculture, 
Washington,  1915,  pp.  21-32. 

Berthon.     Etude  D'un  Peuplement  de  Foret  Jardinee.     Bulletin  de  la  Soci6t6 

Forestiere  de  Franche-Comte  et  Belfort,  Vol.  II,  Besanfon,   191 2,  pp. 

411-418. 
Christen.    Zur  Ermittlung  des  laufenden  Zuwachses  speziell  im  Plenterwalde. 

Schweizerische  Zeitschrift  fur  Forstwesen,  Bern,  1909,  pp.  37-41  and  pp. 

82-87. 
Clapp,  E.  H.     Silvicultural  Systems  for  Western  Yellow  Pine.     Proceedings 

of  the  Society  of  American  Foresters,  Vol.  7,  191 2,  pp.  168-176. 
Fankhauser,  F.     Ueber  die  Notwendigkeit  von  Ertrags  nachweisungen  im 

Plenterwald.     Forstwissenschaftliches  Centralblatt,  1908,  pp.  417-432. 
Frothingham,  E.  H.     The  Eastern  Hemlock.     Bulletin  152,  United  States 

Department  of  Agriculture,  Washington,  1915,  pp.  29-30. 
Frothingham:,  E.  H.    The  Northern  Hardwood  Forest:    Its  Composition, 

Growth  and  Management.     Bulletin  285,  United  States  Department  of 

Agriculture,  Washington,  1915,  pp.  37-39. 
G.   Z.   Privatwald   und   Plenterbetreib.      Schweizerische   Zeitschrift  fur 

Forstwesen,  Bern,  1911,  pp.  247-255. 
Larsen,  L.  T.     Sugar  Pine.     Bulletin  426,   United  States  Department  of 

Agriculture,  Washington,  1916,  pp.  30-33. 
MuNGER,   T.   T.     Western  Yellow  Pine  in   Oregon.     Bulletin   418,   United 

States  Department  of  Agriculture,  Washington,  191 7,  pp.  38-39. 
Murphy,  L.  S.     The  Red  Spruce:    Its  Growth  and  Management.     Bulletin 

S44,  United  States  Department  of  Agriculture,  Washington,   191 7,  pp. 

46-48. 
Wagner,  C.    Blenderwald  oder  schlagweiser  Hochwald.    Forstwissenschaft- 
liches Centralblatt,  Berlin,  1909,  pp.  23-29. 


no  THE   SELECTION  METHOD 

Weidman,   R.   H.     a   Study  of  Windfall  Loss  of  Western  Yellow  Pine  in 

Selection  Cuttings  Fifteen  to  Thirty  Years  Old.      Journal  of   Forestry, 

Vol.  XVin,  1920,  pp.  616-622. 
WoOLSEY,  T.  S.,  Jr.     Cutting  Western  Yellow  Pine  in  Arizona  and  New 

Mexico.     Proceedings  of  the  Society  of  American  Foresters,  Vol.  9.  1914, 

pp.  479-503- 
ZoN,  R.     Balsam  Fir.     Bulletin  55,  United  States  Department  of  Agriculture, 

Washington,  1914,  pp.  65-66. 


CHAPTER  VII 
THE  COPPICE  METHOD 

Definition.  —  A  coppice  forest  is  one  composed  wholly  or 
mainly  of  sprouts  and  the  coppice  method  of  reproduction 
acomplishes  the  renewal  of  the  forest  principally  by  sprouts, 
although  usually  with  a  mixture  of  seedlings.  The  stand  is 
cut  clear  and  reproduction  starts  immediately  by  sprouts 
from  the  stumps  or  roots  of  the  old  stand  and  by  scattered 
seedlings  on  the  ground  at  the  time  of  cutting. 

The  method  is  sometimes  spoken  of  as  simple  coppice  or 
the  sprout  method. 

Form  of  Forest  Produced.  —  The  coppice  method  produces 
an  evenaged  stand,  more  regular  in  form  than  the  majority  of 
those  established  under  other  reproduction  methods.  Sprout 
reproduction  originating  all  in  one  year  explains  this  regu- 
larity. 

Details  of  the  Method.  —  The  coppice  method  requires  only 
one  cutting  which  takes  the  entire  stand  leaving  a  bare  area. 
Within  less  than  a  year  the  sprouts  start  and  the  new  stand 
has  replaced  the  old.  (See  Fig.  40.)  It  is  evident  that  ability 
to  sprout  is  an  essential  requisite  for  any  species  if  it  is  to  be 
reproduced  under  the  coppice  method.  Therefore  the  method 
is  one  more  frequently  used  with  hardwoods  than  with  conifers. 

Sprouts  originate  from  dormant  or  adventitious  buds  and 
with  most  species  start  from  the  root  collar,  side  or  top  of 
the  stump.  Those  from  the  root  collar  are  the  most  abun- 
dant and  develop  into  the  best  trees.  A  few  species  sprout 
mainly  from  the  roots.     Root  suckers  cannot  in  all  cases  be 


^  2 


■5  $ 


-  a 


"S  K) 


DETAILS  OF  THE  METHOD  I13 

depended  upon  to  reach  maturity  as  they  are  apt  to  be  affected 
with  decay  from  the  mother  root. 

It  is  important  to  know  not  only  whether  a  species  sprouts 
but  also  where  the  sprouts  originate  —  from  the  stump  or 
from  the  roots,  and  if  from  the  roots  whether  the  root  suckers 
will  grow  to  merchantable  size. 

A  species  capable  of  reproducing  by  sprouts  does  not  always 
produce  a  satisfactory  crop  of  sprouts.  This  variability  in 
sprout  reproduction  may  be  attributed  to  several  factors  of 
which  the  three  following  are  the  most  important: 

Age  of  the  stump  at  time  of  cutting. 

Season  of  the  year  at  which  the  cutting  is  performed. 

Height  and  character  of  the  stumps  left  by  the  choppers. 

Age  of  the  Stump  at  the  Time  of  Cutting. — As  trees  grow 
older  and  enter  the  period  of  seed  production  their  sprouting 
ability  gradually  decreases.  Beyond  a  certain  age  only  a 
few  trees  of  a  given  species  can  be  counted  on  to  sprout  after 
cutting.  The  age  varies  considerably  between  species.  White 
oak  in  Connecticut  sprouts  feebly  from  stumps  over  60  years 
of  age.  Chestnut  in  Maryland  reaches  its  limit  of  sprouting 
ability  at  120  years  of  age.^  The  thriftier  the  tree  and  the 
nearer  its  maximum  rate  of  growth  when  cut  the  better  does 
the  stump  sprout.  This  period  of  greatest  thrift  and  highest 
growth  rate  comes  during  the  first  part  of  the  tree's  Hfe  and 
may  be  considered  as  passed  by  the  thirtieth  year. 

Season  of  the  Year  at  which  the  Cutting  is  Performed.  — 
The  best  tune  to  do  the  cutting  is  in  the  period  when  the  trees 
are  in  the  dormant  condition.  The  presence  of  sap  in  the 
wood  at  the  time  of  cutting  increases  the  liability  of  the  stumps 
and  sprouts  to  suffer  injuries  such  as  tearing  of  bark,  break- 
ing off  of  sprouts  and  damage  by  frost.  Zon  ^  found  that 
winter  cut  chestnut  sprouted  best;   then  spring  cut. 


114  THE   COPPICE   METHOD 

Mattoon  ^  states  that  sprouts  from  chestnut  trees  cut  in 
May  are  inferior  in  vigor  to  those  from  winter  cut  trees,  at- 
taining approximately  only  half  the  height  and  diameter  of  the 
latter  and  suffering  from  fall  frosts. 

Stumps  cut  in  early  summer  may  sprout,  but  sprouts 
starting  so  late  make  feeble  growth  and  are  killed  by  frost. 
Stumps  cut  after  midsummer  are  likely  to  remain  unproduc- 
tive or  furnish  sprouts  only  in  the  following  year. 

Height  and  Character  of  the  Stumps  Left  by  Choppers.  — 
For  the  most  vigorous  sprout  reproduction  stumps  should  be 
cut  low,  smooth  and  slanting.  A  low  stump  keeps  the  sprouts 
right  at  or  close  to  the  root  collar  as  their  place  of  origin.^ 
This  in  turn  enables  the  sprouts  to  form  independent  root 
systems  quickly.  The  stump  itself  if  cut  low  is  more  com- 
pletely covered  by  dirt,  litter,  or  snow  and  thus  is  better 
protected  against  extremes  of  cold  and  heat.     (See  Fig.  41.) 


Fig.  41. 

Illustrates  good  and  bad  stumps  from  the  standpoint  of  sprout  reproduction. 
Stump  A  is  too  high  and  is  likely  to  produce  sprouts  from  the  top  or  side. 
Stump  B  is  the  best  of  the  four  being  low,  cut  smooth  and  slanting  so  as  to'shed 
water.  Stump  C  is  very  bad  as  the  notch  will  collect  water.  Stump  D  while 
better  than  A  and  C  is  not  so  good  as  B. 

The  axe  should  be  used  in  preference  to  the  saw  for  felling 
where  sprout  reproduction  is  desired.  A  smooth  cut,  par- 
ticularly one  made  on  a  slant  so  that  water  sheds  off  the 
stump,  increases  the  time  during  which  the  stump  will  remain 
sound.  It  is  easy  with  an  axe  to  prepare  such  a  stump. 
Felling  with  the  saw  leaves  stumps  with  relatively  rough 


DETAILS  OF  THE  METHOD  II5 

surfaces,  the  fibers  being  torn  instead  of  smoothly  cut  as  with 
an  axe.  When  a  stump  is  small,  as  is  the  case  under  a  low- 
rotation,  it  may  be  entirely  calloused  over  and  the  entrance 
of  rot  before  this  is  accompUshed  may  be  prevented  by  a 
smooth  cut  stump. 

Since  sprouting  ability  decreases  with  age  and  is  at  its  best 
during  the  first  few  decades  of  a  stand's  life,  it  follows  that 
rotations  for  the  coppice  method  of  reproduction  should  be 
short.  How  short  will  depend  principally  upon  the  inher- 
ent sprouting  abiHty  of  the  species,  together  with  its  rate 
of  growth  and  the  age  at  which  salable  products  can  be 
obtained.^ 

If  vigorous  sprouting  alone  were  to  be  considered,  rotations 
less  than  10  years  in  length  would  be  desirable.  This  is  much 
too  short  to  be  generally  possible,  because  the  products  grown 
would  be  of  small  size  and  salable  only  under  the  most  in- 
tensive market  conditions.  By  extending  the  rotation  to  40 
years  a  good  yield  of  cord  wood  can  be  secured. 

While  this  is  more  profitable  than  the  brushwood  produced 
on  a  rotation  of  less  than  10  years,  it  is  still  an  inferior 
product  and  often  unprofitable.  In  order  to  secure  lumber 
a  rotation  of  60  to  100  years  will  be  found  necessary,  with 
most  of  the  species  which  can  be  reproduced  by  sprouts. 

When  a  very  short  rotation  (less  than  10  years)  is  used, 
reproduction  should  be  fully  stocked  and  vigorous.  With  a 
40  year  rotation  there  may  stiU  be  satisfactory  sprout  repro- 
duction, but  with  60  to  100  year  rotation  sprouts  cannot  be 
counted  on  to  establish  a  fully  stocked  stand.  Even  though 
all  the  stumps  of  the  trees  in  the  old  stand  should  sprout,  the 
stocking  would  be  incomplete  because  these  old  trees  were 
too  few  in  number  and  stood  too  far  apart  to  reproduce  the 
area  completely  by  sprouts. 

When  the  rotation  is  lengthened  to  40  or  more  years  it 


Il6  THE   COPPICE   METHOD 

becomes  necessary  to  provide  for  a  mixture  of  seedling  repro- 
duction to  supplement  the  crop  of  sprouts. 

Decay  from  the  old  stumps  infects  the  sprouts  seriously  on 
a  long  rotation.  It  is  advisable  that  a  certain  amount  of 
seedHng  reproduction  be  secured  from  time  to  time  even  in  a 
stand  fully  stocked  with  sprouts.  This  maintains  the  vigor 
of  the  stand  in  spite  of  the  decay  which  may  weaken  the 
sprouting  ability  of  certain  of  the  stools. 

Seedling  reproduction  can  be  secured  artificially  by  setting 
out  plants  in  the  spots  which  the  sprouts  have  failed  to  stock. 
Strong  transplants  should  be  used  and  after  planting  be  cut 
back  to  the  ground.  They  send  up  vigorous  sprouts  which 
compete  more  successfully  with  the  coppice  than  could  the 
original  transplants.  Fortunately  when  the  rotation  is  length- 
ened to  40  years  or  more  the  parent  stand  is  old  enough  in 
most  cases  to  produce  abundant  seed  and  natural  reproduc- 
tion can  be  relied  upon  to  furnish  a  mixture  with  the  sprouts. 
The  polewood  coppice  method  discussed  in  detail  under 
"Modifications  of  the  Method"  has  been  developed  for  use 
under  such  circumstances. 

It  may  be  necessary  to  assist  the  seedling  reproduction  for 
a  few  years  in  overcoming  competition  with  sprouts.  These 
latter  grow  faster  than  the  seedlings  in  early  life  and  may 
overtop  and  suppress  the  seedling  reproduction  which  it  is 
desired  to  establish. 

In  the  coppice  method  preparation  of  the  site  to  secure 
favorable  conditions  for  germination  and  for  the  development 
of  young  reproduction  is  unnecessary.  The  sprouts  are  able 
to  compete  successfully  with  underbrush,  and  are  independent 
of  htter  conditions  and  ground  cover. 

Disposal  of  the  tops  left  after  the  clearcutting  of  the  area  is 
not  essential  from  the  standpoint  of  satisfactory  reproduction. 
Considerable  accumulations  of  hardwood  brush  do  not  pre- 


MODIFICATIONS   OF  THE  METHOD  117 

vent  the  sprouting  of  stumps  located  under  the  brush,  although 
occasional  stumps  may  be  so  deeply  covered  as  to  smother  the 
sprouts.  Usually  where  the  coppice  method  is  employed  a 
close  utilization  is  possible  and  the  tops  that  remain  are 
relatively  small. 

Since  the  coppice  method  is  a  clearcutting  operation,  it  is 
advisable  that  large  cutting  areas  be  avoided  to  prevent 
exposure  of  the  site.  This  can  be  arranged  by  cutting  in 
alternate  or  progressive  strips  where  danger  of  exposure  makes 
it  advisable. 

Modifications  of  the  Method.  —  The  Polewood  *  Coppice 
Method.  —  This  method  is  intended  for  use  on  coppice  rotations 
of  40  years  or  more  where  a  mixture  of  seedHng  reproduction 
is  wanted  with  the  sprouts. 

The  stand  is  removed  in  two  cuttings  instead  of  the  one 
clearcutting  ordinarily  employed  with  coppice.  The  first 
cutting  is  designed  to  establish  seedling  reproduction  and  is 
in  the  nature  of  a  seed  cutting.  It  removes  the  same  classes 
of  trees  as  the  seed  cutting  under  the  shelterwood  method, 
namely: 

Diseased  and  defective  trees. 
Overtopped  trees. 

Trees  with  overdeveloped  and  spreading  crowns. 
Slender  small  crowned  trees  Hable  to  be  windthrown  and 
those  of  undesirable  species. 

Approximately  30  to  60  per  cent  of  the  volume  of  the  stand 
would  be  taken  out  in  this  first  cutting.  The  per  cent  to  be 
cut  depends  primarily  upon  the  proportion  of  the  area  upon 
which  seedling  reproduction  is  needed.  In  the  average  mixed 
hardwood  stand  (which  is  the  type  where  coppice  is  most  com- 

*  First  named  and  described  by  Henry  S.  Graves  in  "Principles  of  Handling 
Woodlands." 


THE  COPPICE   METHOD 


monly  used),  there  are  some  species  which  will  sprout  vigor- 
ously, even  from  the  stumps  of  trees  cut  when  40  or  more 
years  old,  and  other  species  which  sprout  poorly  or  not  at  all 


A  stand  containing  non-sprouting  and  sprouting  species  mixed  groupwise 
showing  the  location  of  the  areas  occupied  by  each  of  the  two  classes  of  species. 
The  first  cutting  will  extend  only  over  the  areas  occupied  by  non-sprouting 
species. 

from  similar  stumps.  It  is  necessary  that  provision  be  made 
for  seedling  reproduction  to  replace  this  latter  class  of  species. 
The  distribution  of  the  vigorous  and  feeble  sprouters  may 


MODIFICATIONS   OF   THE   METHOD  119 

be  uniform  or  of  a  groupwise  character.  When  it  is  group- 
wise,  patches  of  a  quarter  of  an  acre  or  more  may  be  left 
unstocked  unless  seedling  reproduction  is  obtained. 

The  first  cutting  is  located  with  reference  to  the  distribu- 
tion of  vigorous  and  feeble  sprouting  trees.  Where  there  are 
enough  trees  capable  of  producing  vigorous  sprouts,  seedling 
reproduction  is  not  needed  and  a  seed  cutting  is  not  made  in 
that  spot.  Elsewhere  a  seed  cutting  is  made  to  estabhsh  the 
needed  seedling  reproduction.     (See  Figs.  42,  43,  and  44.) 

The  first  cutting  is  made  3  to  10  years  before  the  end 
of  the  rotation.  When  seedling  reproduction  is  estabHshed 
the  stand  is  ready  for  the  second  and  final  cutting.  This 
removes  the  remainder  of  the  old  stand.  The  area  is  left 
bare  except  for  the  seedling  reproduction  established  pre- 
viously. Sprout  reproduction  starts  soon  from  the  stumps 
capable  of  sprouting  and  joins  with  the  seedlings  to  make  a 
completely  stocked  stand.  The  sprouts  usually  equahze  in 
this  first  year's  growth  the  advantage  in  height  which  sev- 
eral years'  start  had  given  the  seedlings. 

Pollarding.  ■ —  Sometimes  trees  are  severely  trimmed  or 
lopped  back  with  the  intention  of  reproducing  a  growth  of 
sprouts  from  the  portion  of  the  tree  remaining.  The  sprouts 
are  harvested  when  relatively  small  and  another  crop  started. 
This  is  known  as  pollarding.  The  point  of  pollarding  is 
usually  between  4  and  12  feet  above  the  ground. 

Pollarding  may  be  described  as  the  coppice  method  oper- 
ated on  a  short  rotation  and  with  abnormally  high  stumps. 
The  method  is  first  started  when  the  original  trees  are  10  to 
20  years  old.  A  pollard  head  should  remain  productive  for 
60  to  100  years,  but  finally  becomes  useless  or  unproductive 
due  to  the  effect  of  decay.  The  method  is  particularly 
suited  for  use  on  lands  frequently  or  deeply  flooded,  as  the 
pollard  head  keeps  the  tender  sprouts  out  of  the  way  of  injury 


ADVANTAGES  AND   DISADVANTAGES  1 21 

by  water  or  floating  debris  and  prevents  their  being  sub- 
merged. Pollarding  can  be,  and  usually  is,  combined  to 
advantage  with  partial  use  of  the  land  for  grazing  or  agri- 
cultural crops.  The  pollard  heads  are  arranged  far  enough 
apart  so  that  good  grass  for  grazing  can  develop  between 
them,  while  the  sprouts  are  above  the  reach  of  the  animals. 
The  pollard  heads  may  be  placed  still  farther  apart  in  rows 
where  they  serve  as  fence  or  vineyard  posts.  Agricultural 
crops  are  then  grown  between  the  rows  of  pollard  heads.     (See 

Fig.  45-) 

Rotations  in  pollarding  must  be  short,  as  the  individual 
sprouts  cannot  develop  independent  root  systems  and,  if 
allowed  to  reach  large  size,  would  break  off  from  the  pollard 


Fig.  45. 

A  row  of  trees  managed  under  the  method  of  pollarding.  The  young  shoots 
above  the  pollard  heads  are  one  year  old  and  ready  to  be  cut. 

head  often  injuring  the  latter.  From  Lto  15  years, covers  the 
range  in  rotation  with  ages  less  than  five  most  commonly 
employed. 

Advantages  and  Disadvantages  of  the  Method.  —  The 
coppice  method  with  its  comparatively  short  rotation  and 
reproduction  from  sprouts  stands  in  strong  contrast  to  the 
four  high  forest  methods  which  depend  on  reproduction  from 
the  seed.  It  is  to  be  expected  that  there  will  be  distinct 
advantages  and  disadvantages  appl}dng  to  the  coppice  method 
as  compared  with  the  high  forest  methods. 

Advantages.  —  i.  Requires  only  a  small  growing  stock  and 
hence  a  low  financial  investment.     This  is  a  consequence  of 


122  THE   COPPICE   METHOD 

the  short  rotation  used  and  holds  true  particularly  for  the 
very  low  rotations. 

2.  Although  the  wood  produced  is  of  comparatively  small 
size  and  poor  quality,  the  net  return  on  the  investment  is 
relatively  high,  due  primarily  to  the  short  rotation  and  the 
small  amount  of  capital  invested. 

3.  The  period  of  most  rapid  growth  (i.e.,  early  youth)  is 
taken  advantage  of  by  cutting  the  stand  when  this  period  is 
past  and  starting  a  new  crop.  Hence  the  amount  of  wood 
produced  per  year  should  be  greater  than  under  high  forest 
methods.  The  fact  that  sprouts  grow  faster  in  early  Hfe 
than  trees  originating  from  seed  supports  this  theory. 

Short  coppice  rotations,  while  including  the  period  of  most 
rapid  growth  so  far  as  low  grade  products  such  as  cordwood 
are  concerned,  are  not  long  enough  to  grow  large  amounts  of 
better  grade  products  like  lumber.  Therefore  the  advantage 
of  faster  growth  under  the  coppice  method  is  true  only  for 
products  of  small  size. 

4.  Subject  to  comparatively  few  injuries ;  because  the  trees 
are  still  young  and  vigorous  at  the  end  of  the  rotation.  Those 
which  may  occur  can  be  made  good  with  less  sacrifice  than 
under  methods  which  require  longer  rotations. 

5.  The  securing  of  reproduction  by  sprouts  is  simple  and 
certain  as  compared  with  reproduction  from  the  seed. 

Disadvantages.  —  i.  Requires  that  lower  grade  products 
such  as  cordwood  be  salable.  For  intensive  application  on 
rotations  of  less  than  fifteen  years  it  is  necessary  that  a 
market  exist  for  very  small  sized  material.  Except  under 
the  polewood  coppice  method  lumber  forms  only  a  small 
percentage  of  the  yield. 

2.  Coppice  is  unsatisfactory  from  the  standpoint  of  the 
public  welfare  because: 

(a)  It  fails  to  provide  the  lumber  needed  in  the  industries. 


APPLICATION  OF  THE   METHOD  1 23 

This  disadvantage  is  one  having  particular  weight  in  the 
management  of  publicly  owned  lands. 

(6)  It  does  not  provide,  due  to  its  low  growing  stock,  a 
reserve  supply  of  forest  products  for  the  future  or  to  meet 
extraordinary  demands. 

3.  It  is  a  method  which  tends  to  exhaust  the  available 
mineral  substances  in  the  soil,  because  the  product  consists  so 
largely  of  small  branches  and  young  wood  which  contain  a 
greater  proportion  of  minerals  than  larger  and  older  wood."* 

4.  The  sprouts  are  frequently  damaged  by  frost.  Young 
sprouts  are  apt  to  continue  rapid  growth  until  late  in  the 
season  and  fail  to  Hgnify  before  the  fall  frosts.  The  injury 
results  in  the  kilHng  back  of  all  or  parts  of  the  last  year's 
growth  of  the  sprouts  which,  if  not  entirely  killed,  may  con- 
tinue growth  the  following  season.  Frost  injury  may  be  so 
serious  as  to  prevent  the  use  of  the  coppice  method  on  sites 
subject  to  frost,  such  as  the  higher  altitudes. 

5.  ^sthetically  coppice  is  not  a  desirable  method,  since  it 
produces  a  relatively  low  forest  and  one  too  monotonous  in 
its  regularity  to  be  attractive. 

6.  Coppice  is  considered  the  poorest  method  from  the 
protection  standpoint.  The  frequent  clearcuttings  and  the 
relatively  low  total  height  attained  by  the  stand  result  in 
exposure  of  the  site.  The  tendency  of  coppice  to  exhaust 
the  mineral  contents  of  the  soil  is  likely  to  be  important  on 
protection  sites  which  are  usually  shallow-soiled  and  of  poor 
quahty.  The  prompt  start  after  clearcutting  and  the  rapid 
growth  of  reproduction  have  the  effect  of  preventing  the  com- 
plete exposure  of  the  site,  which  may  follow  clearcutting 
with  reproduction  from  the  seed. 

Application  of  the  Method.  —  Coppice  with  its  small  grow- 
ing stock,  low  investment  and  quick  returns  appeals  favor- 
ably to  private  land  owners,  but  is  not  a  satisfactory  method 


124 


THE   COPPICE  METHOD 


for  the  publicly  owned  forest,  because  of  its  failure  to  produce  the 
lumber  required  as  an  economic  necessity  by  the  community. 

Before  a  private  owner  can  avail  himself  of  the  coppice 
method  and  its  attendant  advantages,  there  must  exist  ex- 
cellent markets  for  small  sized  forest  products  and  valuable 
species  suited  to  the  site  and  capable  of  reproducing  by 
sprouts.  The  lack  of  one  or  both  of  these  essentials  pro- 
hibits the  use  of  the  coppice  method  in  many  cases. 

The  coppice  method  as  employed  in  European  countries 
has  been  apphed  principally  in  the  low  lands  adjacent  to 
rivers,  where  the  soils  were  comparatively  rich  and  moist. 
Mountainous  regions  and  other  places  where  the  fall  frosts 
come  so  early  that  the  sprouts  do  not  have  time  during  the 
short  growing  season  to  thoroughly  lignify,  are  unsuited  to 
coppice  production. 

In  Germany  coppice  is  considered  adapted  for  use  at  ele- 
vations below  800  meters. 

Abroad  the  rotations  are  very  low  ranging  from  one  year 
for  willow  rods  for  baskets,  up  to  5  to  1 5  years  for  brushwood, 
hoop  poles  and  vine  props,  and  oak  tanbark  and  rarely  as 
high  as  20  to  40  years  for  cordwood. 

In  the  State  Forests  of  France  which  are  reproduced  under 
the  coppice  method,^  the  areas  may  be  classified  according  to 
length  of  rotation  as  follows : 


Length  of  rotation 

Under  lo 
years 

10-19 

years 

20-29 
years 

30  or  more 
years 

Per  cent  occupied  of  the  area  in 
coooice              

i-S 

32 

56 

10.5 

Greeley^  states  that  30  per  cent  of  the  private  forests  of 
France  are  managed  for  the  production  of  hardwood  fuel  on 
20  year  rotations. 


REFERENCES  1 25 

In  North  America  the  principal  field  for  the  coppice  method 
lies  within  the  Central  Forest  region  ^  and  in  adjacent  portions 
of  the  northern  and  southern  forest  regions.  There  the  re- 
quirements for  species  of  good  sprouting  ability  can  be  met. 
The  coppice  method  is  being  applied  in  many  places  all 
through  this  general  district. 

Usually  certain  special  market  requirements  for  one  or 
more  forest  products  have  led  to  the  development  of  coppice 
stands. 

The  culture  of  the  basket  willow  is  an  example  of  coppice 
production  on  the  shortest  possible  rotation  — ■  one  year.^ 

Clearcutting  of  hardwood  stands  with  sprout  reproduc- 
tion on  rotations  of  20  to  40  years  for  cordwood  to  be  burned 
in  brick  yards,  lime  kilns  and  brass  mills  or  converted  into 
charcoal  for  industrial  uses  has  been  systematically  employed 
in  the  past  and  is  still  in  operation  in  various  parts  of  the 
country. 

In  the  prairie  region  and  other  sections  having  a  large  per- 
centage of  agricultural  land  in  comparison  to  forest  soils,  the 
markets  for  small  hardwood  material  for  posts  or  fuel  are 
sufficiently  good  to  make  profitable  their  production  in  coppice 
stands.  Often  such  stands  may  be  established  as  plantations 
to  be  reproduced  and  handled  thereafter  under  the  coppice 
method. 

The  Eucalypts  which  have  been  introduced  into  CaHfornia 
can  be  handled  successfully  in  coppice  stands. 

REFERENCES 

1.  ZoN,  Raphael.  Chestnut  in  Southern  Maryland.  Bulletin  53,  Bureau 
of  Forestry,  United  States  Department  of  Agriculture,  Washington,  1904. 

2.  Mattoon,  W.  R.  The  Origin  and  Development  of  Chestnut  Sprouts. 
Forestry  Quarterly,  Vol.  VII,  1909,  pp.  34-37. 

3.  Williamson,  A.  W.     Cottonwood  in  the  Mississippi  Valley.     Bulletin 


126  THE   COPPICE  METHOD 

24,  United   States   Department  of  Agriculture,  Washington,  1913,  pp. 17-18 
and  p.  30. 

4.  NiSBET,  J.     Studies  in  Forestry.     Oxford,  1894,  p.  88. 

5.  Martin.  Mitteilungen  uber  forstliche  Verhaltnisse  in  Frankreich. 
Forstwissenschaftliches  Centralblatt,  Berlin,  1909,  pp.  203-208. 

6.  Greeley,  W.  B.  Private  Forestry  in  France.  American  Forestry,  Vol. 
26,  1920,  p.  139. 

7.  Natural  Forest  Regions  of  North  America.  A  map  issued  by  the  Office 
of  Geography  and  the  Dendrologist,  Forest  Service,  United  States  Department 
of  Agriculture,  Washington,  1910. 

8.  Hubbard.  W.  F.  The  Basket  Willow.  Bulletin  46,  Bureau  of  Forestry, 
United  States  Department  of  Agriculture,  Washington,  1904. 

Bagneris,  G.  Elements  of  Sylviculture.  Translated  from  the  French  (2nd 
edition),  by  E.  E.  Fernandez  and  A.  Smythies,  B.A.,  London,  1882,  pp. 

III-I33- 

Mattoon,  W.  R.  Life  History  of  Shortleaf  Pine.  Bulletin  244,  U.  S.  De- 
partment of  Agriculture,  Washington,  1915,  pp.  20-25. 

Reuss,  Hermann.  Die  Forstliche  Bestandesbegriindung,  Berlin,  1907,  pp. 
349-360. 


CHAPTER  VIII 
THE   COPPICE   WITH   STANDARDS   METHOD 

Definition.  —  "A  method  of  reproduction  in  which  seed- 
ling trees  or  selected  sprouts  (standards)  are  maintained  above 
a  coppice  or  sprout  forest."  The  definition,  taken  from  "  For- 
est Terminology,"  ^  indicates  the  salient  features  of  the  method. 
Reproduction  is  from  sprouts  as  in  the  coppice  method,  but 
the  area  is  never  cut  entirely  clear.  Selected  trees  called 
standards  are  left  standing  at  the  end  of  each  coppice  rota- 
tion.    The  method  is  also  known  as  Compound  Coppice. 

Form  of  Forest  Produced.  —  Several  age  classes  are  found 
in  compound  coppice  stands.  The  young  coppice  itself  is  all 
of  one  age  and  presents  a  uniform  appearance.  Above  the 
coppice  are  standards  belonging  to  several  different  age  classes, 
each  one  of  which  is  a  multiple  of  the  rotation  age  of  the  cop- 
pice. The  form  of  stand  produced  is  one  of  several  stories, 
each  evenaged  but  combined  to  create  an  irregular  stand. 

Details  of  the  Method.  —  The  Coppice  with  Standards 
method  is  most  easily  understood  by  taking  ordinary  coppice 
as  the  starting  point  and  following  step  by  step  the  develop- 
ment of  a  compound  coppice  stand.  When  the  coppice  reaches 
the  end  of  the  rotation  instead  of  being  cut  clear,  certain  trees 
or  standards  are  carefully  selected  and  retained,  the  balance 
of  the  coppice  being  cut.  The  sprouts  which  follow  the  cut- 
ting form  a  distinct  story  under  and  between  the  standards. 

A  second  rotation  of  the  coppice  passes  and  at  its  end 
standards  are  again  selected  from  among  the  best  trees  in  the 
coppice  and  the  remainder  is  cut.     Some  of  the  standards  left 


128  THE  COPPICE  WITH  STANDARDS  METHOD 

at  the  end  of  the  first  coppice  rotation  may  be  taken  out  but 
the  better  ones  are  left.  After  this  cutting  three  distinct  age 
classes  or  stories  are  represented,  —  the  older  standards  now 
twice  the  age  of  the  coppice  rotation,  the  younger  standards 
of  an  age  equivalent  to  the  coppice  rotation,  and  finally  the 
new  generation  of  sprouts  springing  up  from  the  recently  cut 
coppice.  This  process  may  be  continued  through  as  many 
coppice  rotations  as  desired,  increasing  by  one  for  each  suc- 
ceeding cutting  of  the  coppice  the  number  of  age  classes 
occurring  on  the  area.  Eventually  the  older  standards  reach 
the  age  assigned  for  their  rotation  which  will  be  a  multiple  of 
the  coppice  rotation.  When  this  occurs,  the  oldest  age  class 
of  standards  is  cut,  at  the  same  time  that  the  coppice  is  har- 
vested, and  the  poorest  trees  removed  from  the  other  classes 
of  standards.  From  this  point  on,  the  number  of  age  classes 
on  the  area  remains  constant.  (See  Figs.  46,  47,  48  and  49.) 
Where  more  than  one  species  is  reserved  as  standards,  there 
may  be  a  different  rotation  for  the  standards  of  each  species. 

Sprout  reproduction  is  refied  upon  to  maintain  the  coppice. 
This  is  possible  because  of  the  low  rotation.  The  standards 
when  finally  harvested  are  usually  too  old  to  sprout.  There 
may  be  a  small  area  around  the  stump  of  a  standard  which 
is  not  stocked.    If  such  is  the  case  the  gap  is  filled  by  planting. 

Since  the  standards  Hve  through  several  coppice  rotations, 
the  danger  of  their  becoming  infected  with  fungi  is  great,  if 
they  originate  from  sprouts.  Standards  of  seedling  origin 
are  less  liable  to  such  injuries  than  are  trees  of  sprout  origin; 
hence  it  is  desirable  that  most  of  the  standards  have  seedling 
origin.  There  may  be  a  sufficient  mixture  of  seedling  repro- 
duction starting  naturally  with  each  new  crop  of  coppice.  In- 
deed the  presence  of  standards  capable  of  furnishing  seed  tends 
to  bring  in  more  seedling  reproduction  than  occurs  in  simple 
coppice  stands.     When  natural  seedlings  of  the  right  species 


^    ID 


&:=^ 


a=3il 

CO 

»  =  § 
1^1 

o 

d  2^'H 

K-l 

5 

S-S^ 

II 

>.'2^ 

XW^ 

o^^ 

:^ 

-dS^ 

xW 

ISI 

Ji's! 

•     Ci<.y   u 

^P 

^ 

c3 

^1^- 

n^ 

^. 

|i| 

m 

r3 

o 

u  = 


.5 
S 

ll 


Id   ^ 


-a  .5 

G     S 


130 


132  THE   COPPICE   WITH   STANDARDS   METHOD 

are  available,  the  standards  should  be  selected  from  among 
them.  If  seedlings  are  lacking,  it  becomes  necessary  to  make 
provision  for  new  standards  by  planting  seedhng  trees  among 
the  stools  when  the  coppice  is  cut.  Plants  for  this  purpose 
should  be  large,  strong  transplant  stock  to  compete  with  the 
sprouts.  If  the  species  planted  reproduces  vigorously  by 
sprouts,  the  transplants  after  being  set  out  can'  be  cut  back 
carefully  to  the  ground  level.  One  or  more  vigorous  sprouts 
start  and  compete  more  successfully  with  the  coppice  sprouts 
than  the  original  transplant  could  have  done.  If  several 
sprouts  arise  the  number  should  be  reduced  to  one.  Such 
sprouts,  termed  ''seedling  sprouts,"  have  the  rapid  initial 
growth  of  true  sprouts,  combined  with  the  relative  hardiness 
against  disease  possessed  by  trees  of  seedhng  origin. 

The  standards  and  coppice  may  or  may  not  be  of  the  same 
species.  In  general  light-foHaged  species  are  favored  as  stand- 
ards, while  trees  capable  of  thriving  under  a  partial  cover  are 
desirable  in  the  coppice.  The  coppice  furnishes  cordwood 
and  other  products  of  smaller  size,  hence  the  species  in  the 
coppice  must  produce  wood  which  has  a  value  while  still 
young.  Standards  grow  until  large  enough  for  lumber  and 
should  be  chosen  for  their  abihty  to  grow  throughout  several 
coppice  rotations  and  for  the  value  of  their  lumber  yield.  It 
is  often  desired  to  introduce  a  species  not  found  on  the  site  as  a 
standard.  A  conifer  of  high  timber  producing  value  may 
thus  be  employed  as  a  standard  over  hardwood  coppice. 

Rotations  for  the  coppice  range  up  to  25  years,  which  is  as 
long  an  interval  as  should  ensue  between  cuttings  among  the 
trees  in  the  various  age  classes  of  standards.  The  coppice 
rotation  may  be  as  much  lower  than  25  years  as  markets  for 
the  small  products  permit;  but  good  standards  cannot  be 
produced  unless  the  coppice  is  grown  on  a  relatively  long  rota- 
tion and  becomes  high  enough  to  provide  standards  with 


DETAILS   OF  THE  METHOD  I33 

fairly  clear  boles.  The  rotation  for  the  standards  may  be 
any  multiple  of  the  coppice  rotation.  Rarely  would  it  be 
advisable  to  extend  such  a  rotation  longer  than  four  or  five 
times  the  length  of  the  coppice  rotation. 

In  selecting  trees  to  be  left  as  standards,  the  question  arises 
as  to  how  many  should  be  left  per  acre.  This  is  contingent 
not  only  upon  the  silvical  habits  of  the  species,  particularly 
their  Hght  requirements  and  spread  of  crown,  but  primarily 
upon  the  relative  extent  to  which  the  standards  as  contrasted 
to  the  coppice  are  to  be  favored. 

There  may  be  distinguished  three  forms  of  coppice  with 
standards  ^  depending  on  the  relation  between  the  standards 
and  coppice. 

(a)  Compound  coppice  approaching  simple  coppice,  where 
the  overwood  of  standards  is  distributed  by  single  trees  of 
only  a  few  age  classes  and  occupies  a  small  part  of  the  area. 
Firewood  is  the  chief  product. 

(b)  Normal  compound  coppice,  in  which  the  sprouts  and 
the  standards  are  of  equal  importance  and  both  cordwood 
and  timber  are  produced  in  quantity. 

(c)  Compound  coppice  approaching  high  forest,  in  which 
the  standards  occupy  a  large  part  of  the  area,  usually  in 
groups,  and  the  coppice  possesses  the  importance  only  of  a 
soil  protecting  cover.     Timber  is  the  principal  product. 

These  three  forms  indicate  the  possible  field  of  variation  in 
mixture  of  sprouts  and  standards,  which  is  available  between 
a  stand  composed  of  coppice  sprouts  or  a  high  forest. 

Area  covered  by  the  spread  of  the  crowns  is  the  basis  for 
judging  the  part  of  the  stand  occupied  by  the  standards. 
The  percentage  of  the  total  area  allotted  to  the  standards 
should  be  decided  upon  before  any  cuttings  are  made. 

After  determining  the  portion  of  the  total  area  to  be  de- 
voted to  standards,  it  should  be  apportioned  equally  among 


134  THE   COPPICE  WITH  STANDARDS  METHOD 

the  several  age  classes  of  standards  which  will  be  present.  If, 
for  example,  0.5  of  the  area  is  allotted  to  standards  and  there 
are  five  age  classes  of  standards  on  a  rotation  of  120  years, 
with  a  coppice  rotation  of  20  years,  then  o.i  of  the  area 
should  be  occupied  by  the  standards  of  each  age.  Each  age 
class  of  standards  occupies  the  same  area  as  it  increases  in 
age  throughout  the  rotation.  As  a  necessary  corollary  each  age 
class  of  standards  must  contain  more  trees  when  first  estab- 
lished than  at  the  end  of  the  rotation,  because  each  indi- 
vidual tree  occupies  more  space  with  increase  in  age.  In 
order  to  keep  the  area  occupied  by  standards  of  a  given  age 
approximately  constant,  it  is  necessary  to  reduce  their  num- 
ber occasionally.     (See  Fig.  50.) 

This  is  done  at  the  time  the  coppice  is  cut  clear.  Where 
standards  are  in  dense  groups  overtopped,  intermediate  or  co- 
dominant  trees  may  be  cut  in  a  thinning  without  decreasing 
the  area  filled  by  the  age  class,  but  in  addition  other  standards 
must  be  cut,  which  will  actually  reduce  temporarily  the  area 
occupied  by  that  class. 

The  relative  number  of  standards  at  different  ages  must  be 
worked  out  for  each  species  and  situation.  The  following 
illustration  for  oak  in  a  European  forest  is  cited  by  Graves^: 

Number  of  Standards 

100  years  old i 

80  years  old 2 

60  years  old 3 

40  years  old 12 

20  years  old 20 

A  uniform  distribution  of  standards  over  the  area  need  not 
be  attempted.  They  may  be  left  singly,  wherever  desirable 
trees  for  standards  occur  among  the  coppice,  or  in  groups. 


DETAILS  OF  THE  METHOD 


f35 


This  latter  plan  has  especial  merit  for  conifers,  introduced 
artificially,  in  producing  clearer  boles. 

The  isolated  position  of  the  standards  with  full  Hght  from 
all  sides,  particularly  for  a  few  years  after  the  periodic  cutting 
of  the  coppice,  often  results  in  the  formation  of  epicormic 


\^  \/Standard\     \.  \. 
\  \       40  Years  k     \    \ 

\J^>-— ^  /StandardV 
60  Years    ^^1^ 

^ 

\  \ 

\\VV 

^of  Age     y^O\/ 

standard           \0 
100  Years            ^^ 

\\ 

\      X^taii'l'i'^^ 

of  Age 

K 

\.  \,  \ 

\    I  40  Years  h 

\     \.       N^X        ^\ 

/\ 

i^ 

\.     \\of  Age  / 

\,^    N,     /Standardyx 
\    \.      \(  40  Years  ) 
\\Vof  Age/\ 

x^Tx^ 

X 

/^standard 
60  Years 

ix^ 

Q  o\p\pX^?^^ 

standard  A 

I    of  Age 

Standard      \ 
80  Years     I  ^ 

\/standard\v  \. 
\     [     60  Years    )\. 
M     of  Age    /\y 

Standard 

80  Years 

of  Age 

60  Years    K 
of  Age/\ 

\\\ 

of  Age      /  \ 

\/standard\\   \     ^ 
.    (  40  Years  K/X    \^ 

Xx 

TStandard^. 
40  Years  t\ 

\v\ 

^WV^ 

^v  of  AgeX    n\\^ 

\...\      \ 

\of  Age/. 

Fig.  so. 

An  illustration  of  the  distribution  of  the  area  between  the  coppice  and  each 
age  class  of  the  standards.  The  stand  is  assumed  to  be  at  the  end  of  a  20  year 
coppice  rotation  just  before  the  cutting.  Rotation  for  the  standards  is  100 
years.  In  this  diagram  0.6  of  the  total  area  is  in  coppice.  The  balance,  0.4 
of  the  total  area,  is  equally  distributed  between  the  40,  60,  80  and  100  year  old 
standards.  The  new  standards,  20  years  in  age,  to  be  left  after  the  cutting  of 
the  coppice  are  included  in  the  area  allotted  to  the  latter.  The  100  year  old 
standards  will  be  cut  in  the  same  operation  and  the  new  20  year  old  standards 
will  occupy  the  area  otherwise  lost  to  the  standard  classes  by  cutting  the  old 
trees. 


JH  C.  State  Co/^ - 

136  THE  COPPICE  WITH  STANDARDS  METHOD 

branches  on  trees  which  have  not  an  adequate  crown  devel- 
opment.^ Pruning  to  remove  such  branches  is  advisable,  as 
an  otherwise  clear  stem  may  be  rendered  knotty. 

Modifications  of  the  Method.  —  There  are  none  which  merit 
special  consideration. 

Advantages  and  Disadvantages  of  the  Method.  —  Coppice 
with  standards  occupies  a  position  intermediate  between  simple 
coppice  and  the  high  forest  methods,  though  nearest  in  character 
to  the  former,  and  shares  in  a  lesser  degree  the  advantages  and 
disadvantages  of  coppice  as  contrasted  with  high  forest. 

Advantages.  —  i.  The  benefit  of  rapid  growth  of  individual 
trees  in  an  open  stand  is  secured  without  danger  of  exposing 
the  soil.  The  standards  grow  in  isolation  throughout  a  large 
part  of  their  hfe,  while  the  coppice  protects  the  site.  Equally 
rapid  growth  of  individual  trees  cannot  be  obtained  under- 
high  forest  methods  without  exposure  of  the  site  or  expensive 
under-planting. 

This  advantage  is  greatest  with  species  whose  timber  value 
per  thousand  feet  board  measure  is  appreciably  enhanced  as 
diameter  increases. 

2.  Does  not  require  so  large  a  growing  stock  or  financial 
investment  as  do  high  forest  methods. 

3.  The  net  return  on  the  investment  is  relatively  high,  due 
to  the  amount  of  capital  invested  and  in  some  cases  to  high 
prices  received  for  material  of  large  size. 

The  follo\\ing  illustration  taken  from  experience  in  Baden 
wiU  illustrate  the  effects  of  advantages  2  and  3.^ 


High  forest 

Compound  coppice 
Simple  coppice  .  .  . 


Annual  cut  per 
acre 


Cubic  feet 
62.86 
65.68 
58.62 


On  a  growing 
stock  of 


Cubic  feet 

3461 

1642 

600 


Volume 
growi;h, 
per  cent. 


1.82 
4.00 
9.76 


ADVANTAGES  AND   DISADVANTAGES  137 

4.  Furnishes  excellent  protection  both  to  the  site  and  to 
the  stand  against  injuries  by  frost,  heat  and  wind.  In  these 
respects  the  method  resembles  selection.  Since  the  younger 
standards  are  always  on  the  ground,  a  partial  cover  is  con- 
stantly maintained  and  the  coppice  springing  up  quickly 
after  each  cutting  affords  additional  protection.  The  stand- 
ards are  windfirm,  having  been  gradually  accustomed  to 
greater  and  greater  exposure,  while  by  their  cover  they  pro- 
tect the  young  coppice  from  frost,  excessive  drouth  and 
evaporation. 

5.  Coppice  with  standards  is  aesthetically  a  desirable 
method  to  use.  Although  less  irregular  in  appearance  than  a 
selection  forest,  a  compound  coppice  stand  permits  develop- 
ment of  fine  individual  trees,  contains  several  age  classes  at 
all  stages  and  does  not  produce  the  regular  form  which  is  a 
consequence  of  the  use  of  certain  other  methods. 

6.  The  natural  factors  of  the  site  are  utilized  to  the  fullest 
extent,  because  the  root  systems  of  the  coppice  underwood 
and  the  several  age  classes  of  standards  penetrate  to  different 
depths  in  the  soil,  and  the  crowns  are  arranged  correspondingly 
at  different  heights. 

7.  As  compared  with  simple  coppice,  compound  coppice  has 
the  advantage  of: 

(a)  Abundant  seed  production  by  the  standards,  thus  pro- 
viding for  an  excellent  representation  of  seedling  trees  among 
the  coppice  sprouts. 

{b)  Permits  the  production  of  considerable  saw  timber  and 
with  a  larger  growing  stock  provides  more  adequately  for 
future  demands. 

Disadvantages.  —  i.  Requires  a  high  degree  of  skill  in  the 
application  of  silviculture  and  in  the  regulation  of  the  amount 
to  be  cut.  This  comes  from  the  complicated  form  of  stand 
which  must  be  maintained  and  from  the  fact  that  in  the  man- 


138  THE  COPPICE  WITH  STANDARDS  METHOD 

agement  of  the  standards  more  consideration  is  given  the 
requirements  of  the  individual  tree  than  is  the  case  under 
other  methods. 

2.  Although  timber  is  likely  to  be  the  principal  product, 
yet,  just  as  with  simple  coppice,  there  must  be  a  market  for 
cordwood  or  other  low  grade  products. 

3.  The  standards  being  grown  in  relatively  open  position 
may  have  a  poor  tree  form,  short  clear  length  and  large 
branching  top.  On  poor  soils  this  is  more  to  be  feared  than 
on  deep  moist  soils.  On  the  former  class  of  soils  compound 
coppice  should  not  be  used.  This  defect  can  be  remedied  to 
some  extent  by  pruning.  With  hardwood  timber,  compara- 
tively clear  wood  of  wide  dimension  is  more  desirable  than 
trees  of  smaller  size  entirely  clear  of  knots. ^ 

4.  Coppice  with  standards  makes  relatively  high  demands 
on  the  fertiHty  of  the  soil,  though  not  so  exacting  in  this  re- 
spect as  simple  coppice.  For  this  reason  Schwappach*"  con- 
siders the  method  suited  to  rich  bottomlands  subject  to 
inundation,  and  states  that  only  on  such  situations  will  the 
volume  of  money  returns  equal  those  secured  from  high 
forest. 

Application  of  the  Method.  —  Compound  coppice  is  of  an- 
cient origin  in  Europe,  the  reserving  of  standards  having  been 
tried  previous  to  1600.  The  method  fell  into  disfavor  due  to 
the  intensive  silvicultural  and  regulation  practice  necessitated. 

In  North  America  silviculture  has  not  been  practiced  long 
enough  to  furnish  complete  examples  of  such  a  compHcated 
method  of  reproduction  as  coppice  with  standards. 

There  is  good  reason  to  beheve  that  it  will  be  employed 
throughout  much  the  same  general  regions  as  simple  coppice 
and  be  applied  by  private  owners  rather  than  on  public 
forests,  for  reasons  similar  to  those  given  on  page  123. 

For  the  production  of  white  oak,  white  ash,  and  tuliptree 


CONVERSION  INTO  HIGH   FOREST  139 

in  stands  of  mixed  hardwoods,  and  for  the  introduction  of  a 
small  mixture  of  conifers  into  stands  of  hardwood  coppice, 
compound  coppice  is  likely  to  find  favor  in  the  future.  The 
owner  of  a  small  area  of  woodland  who  desires  to  grow  a 
little  large  sized  timber  in  addition  to  fuel  for  home  use  will 
find  the  method  useful. 

Due  to  the  protection  from  frost  afforded  the  sprouts  by 
the  standards,  compound  coppice  can  be  used  at  higher  ele- 
vations than  simple  coppice.  It  should  be  confined  to  soils 
of  good  or  at  least  average  quality. 

Conversion  of  Coppice  and  Coppice  with  Standards  into  High 
Forest.  —  In  European  countries,  particularly  France,  the 
tendency  during  the  last  few  decades  has  been  toward  the  con- 
version of  coppice  and  coppice  with  standards  forests  into  high 
forests.  The  principal  cause  for  this  change  in  method  is  the 
relatively  low  prices  prevaiHng  for  fuel  wood. 

The  method  employed  in  accompKshing  this  transforma- 
tion, ^'  "^  ^"'J  ^-  briefly  stated,  consists  in: 

First,  lengthening  the  rotation  to  such  ages  that  the  coppice 
stools  when  cut  will  fail  to  sprout;  and 

Second,  in  making  reproduction  cuttings  of  the  shelterwood 
type  to  estabHsh  seedHng  reproduction. 

Shelterwood  is  a  desirable  method  for  reproducing  most  of 
the  species  found  in  the  coppice  stands.  By  the  process 
described,  the  sprout  stands  can  be  transformed  gradually 
into  excellent  high  forest. 

A  similar  procedure  will  undoubtedly  be  applied  to  some  of 
the  coppice  stands  in  this  country.  With  the  virulent  sprout- 
ing ability,  rapid  growth  and  merchantability  on  relatively 
short  rotations  of  numerous  native  hardwood  species,  it  is 
likely  that  use  of  the  polewood  coppice  method  will  in  certain 
sections  of  this  country  obviate  the  necessity  of  ever  com- 
pletely converting  coppice  stands  to  high  forest. 


I40  THE  COPPICE  WITH  STANDARDS   METHOD 


REFERENCES 

1.  Forest  Terminology,  Journal  of  Forestry,  Vol.  XV,  1917,  p.  91. 

2.  Hamm,  Julius.     Der  Ausschlagwald,  Berlin,  1896. 

3.  Graves,  H.  S.  Principles  of  Handling  Woodlands.  Wiley  &  Sons,  Inc., 
New  York,  1911,  p.  187. 

4.  Hamm,  Julius.  Auen-Mittelwald  und  Lichtwuchs.  Schweizerische  Zeit- 
schrift  fur  Forstwesen,  Bern,  1907,  pp.  149-155  and  pp.  202-208. 

5.  ScHWAPPACH,  Adam.  Forestry.  Translated  from  the  German  by 
Eraser  Story  and  Eric  A.  Nobbs,  London,  1904. 

6.  Hawes,  a.  F.  Conversion  of  Coppice  Under  Standards  to  High  Forests 
in  Eastern  France.     Forestry  Quarterly,  Vol.  6,  1908,  pp.  151-157. 

7.  SanTH,  F.  A.  O.  The  Conversion  of  Underwood  and  Coppice  with 
Standards  into  Highwood.  Quarterly  Journal  of  Forestry,  Vol.  2,  London, 
1908,  pp. 154-165. 

8.  MacMillan,  H.  R.  Conversion  Methods  —  A  Visit  to  the  Forests  of 
Chaux  and  Faye  De  La  Montrond,  France.  Forestry  Quarterly,  Vol.  14,  1916, 
pp.  599-604. 

Bagneris,  G.  Elements  of  Sylviculture.  Translated  from  the  French  (2nd 
edition)  by  E.  E.  Fernandez  and  A.  Smythies  B.A.  London,  1882,  pp. 
133-176. 

KiTTREDGE,  J.,  Jr.  Silvicultural  Practice  in  Coppice  Under  Standard  Forests 
of  Eastern  France.     Journal  of  Forestry,  Vol.  18,  1920,  pp.  512-521. 

Mathey,  M.  a.  Traitement  et  Amenagement  d'un  taillis  sous  futaie.  Bulle- 
tin de  la  Societe  Forestiere  de  Franche-Comte  et  Belfort,  Besangon,  1909, 
pp.  221-227. 


CHAPTER  IX 

INTERMEDIATE  CUTTINGS 

Treatment  of  the  Stand  during  that  Portion  of  the  Rotation 
not  included  in  the  Period  of  Regeneration 

Definition  and  General  Considerations.  —  The  period  of 
regeneration  comes  at  the  end  of  the  stand's  life  and  covers, 
for  all  evenaged  stands,  only  a  small  portion  of  the  rotation. 
Throughout  the  greater  part  of  its  life  from  the  time  of  estab- 
hshment  on  until  the  reproduction  period  arrives,  cuttings  are 
needed  at  varying  intervals  and  for  different  specific  pur- 
poses, although  all  with  the  common  aim  of  correcting  the 
defects  of  the  unmanaged  forest  and  increasing  the  amount 
and  value  of  the  timber  produced. 

All  cuttings  made  during  tliis  period  are  termed  interme- 
diate cuttings. 

Intensive  practice  of  silviculture  demands  that  intermediate 
cuttings  be  apphed  systematically  throughout  the  rotation, 
in  order  to  realize  the  highest  returns.  Unfortunately,  inter- 
mediate cuttings,  which  in  general  do  not  create  permanent 
openings  in  the  forest  canopy,  remove  material  that  is  of 
relatively  poor  quahty  and  small  size  as  compared  with  the 
trees  left.  As  a  consequence  they  cannot  always  be  made 
with  immediate  financial  profit  where  opportunities  for  selHng 
such  products  are  lacking.  Frequently  an  actual  cash  outlay 
will  be  required.  Such  an  expenditure  may  be  fully  justified 
by  the  future  returns  to  be  derived,  but  require  too  much  of  a 
present  investment  to  meet  the  owner's  circumstances.  There 
win  be  many  forests  where  intermediate  cuttings  cannot  be 


142  INTERMEDIATE   CUTTINGS 

made   under    the   existing   conditions   for   marketing   forest 
products. 

The  principles  of  intermediate  cuttings  apply  to  stands 
reproduced  under  any  of  the  standard  methods  of  repro- 
duction. 

Classification  of  Intermediate  Cuttings.  —  The  classifica- 
tion of  intermediate  cuttings  is  a  matter  upon  which  com- 
plete agreement  is  lacking.     As  given  below,  the  classifica- 
tion varies  somewhat  from  the  one  in" Forest  Terminology" 
which  can  be  condensed  to  advantage.     See  Appendix. 

Classification  of  Intermediate  Cuttings 

Cleaning.  —  A  cutting  made  in  a  young  stand,  not  past 
the  sapHng  stage,  for  the  purpose  of  freeing  the  trees  from 
other  individuals  of  similar  age  but  of  undesirable  form  or 
species  which  are  overtopping  or  are  likely  to  overtop  the 
former  trees.  The  terms  "  assistance  cutting,"  ^  "  disengage- 
ment cutting,"  2  "release  cutting"  and  "  weeding,"  ^  are 
synonymous. 

Liberation  Cutting.  —  A  cutting  made  in  an  immature 
stand  for  the  purpose  of  freeing  the  young  growth  from  older 
individuals  (wolf  trees)  which  are  overtopping. 

Thinning.  —  A  cutting  made  in  an  immature  stand  for  the 
purpose  of  increasing  the  rate  of  growth  of  the  trees  that 
remain  and  the  total  production  of  the  stand. 

Improvement  Cutting.  —  A  cutting  made  in  a  stand  past 
the  saphng  stage  for  the  purpose  of  improving  the  composition 
and  character  by  removing  trees  of  undesirable  species,  form 
and  condition. 

Salvage  Cutting.  —  A  cutting  made  for  the  purpose  of 
removing  trees  killed  or  damaged  by  various  injurious  agen- 
cies, of  which  fungi,  insects,  and  fire  are  the  most  serious. 


EVENAGED  VERSUS  UNEVENAGED  STANDS 


143 


Severance  Cutting.  —  A  cutting  made  by  clearing  a  nar- 
row strip  along  the  edge  of  a  young  stand  for  the  purpose  of 
developing  a  belt  of  windfirm  trees  along  the  border  of  the 
stand. 

Pruning.  —  A  cutting  which  removes  branches  from  stand- 
ing trees  for  the  purpose  of  increasing  the  quality  of  the  final 
product. 

A  detailed  discussion  of  the  various  intermediate  cuttings 
will  be  found  in  the  succeeding  pages. 

During  the  life  of  a  stand  there  may  or  may  not  be  need  of 
applying  all  kinds  of  intermediate  cuttings;  but  if  applied 
they  are  hkely  to  occur  in  the  following  order: 


Kind  of  cutting 

Time  of  application 

Remarks 

I  St  to  20th  year 

I  St  year  to  middle  age 

Frequently  unnecessary 
Frequently  unnecessary 

Liberation  cutting. .  . 

Thinning 

20th  year  to  beginning 
of  period   of  regen- 
eration 

Needed  in  all  fully 
stocked  stands 

Improvement  cutting 

20th  year  to  beginning 
of  period   of  regen- 
eration 

Usually  required  in 
mixed  stands  previ- 
ously unmanaged 

Salvage  cutting 

20th  year  to  beginning 
of  period  of  regener- 
ation 

Used  only  in  case  of  in- 
jury to  the  stand 

Severance  cutting 

ist  quarter  of  the  ro- 
tation 

An  intensive  operation, 
little  used  as  yet 

Pruning 

I  St  quarter  or  half  of 
the  rotation 

Advisable  only  in  spe- 
cial cases 

Application  in  Evenaged  versus  Unevenaged  Stands.  —  In 

unevenaged  stands  the  details  of  applying  the  principles  are 
different  from  those  employed  in  evenaged  stands.  The  prac- 
tice in  the  latter  form  of  stand  is  the  simpler  and  will  be  used 
as  the  basis  in  discussing  the  different  kinds  of  intermediate 
cuttings  except  when  otherwise  specifically  stated.     In  the 


144  INTERMEDIATE   CUTTINGS 

evenaged  stand  each  kind  of  intermediate  cutting  is  applied 
as  a  separate  operation,  conducted  independently  of  repro- 
duction cuttings  or  other  kinds  of  intermediate  cuttings,  and 
extends  more  or  less  uniformly  over  the  whole  area.  In  the 
unevenaged  stand  the  period  of  regeneration  is  co-extensive 
with  the  rotation  and  there  may  appear  to  be  no  opportunity 
for  intermediate  cuttings.  But  reproduction  is  not  in  progress 
continuously  in  all  parts  of  the  stand.  Each  year  certain 
small  patches  scattered  through  the  stand  are  reproduced. 
When  reproduction  is  once  established  on  these  patches,  the 
period  of  regeneration  closes  so  far  as  they  are  concerned. 
Any  cuttings  made  in  these  small  areas  during  the  remainder 
of  the  rotation  will  be  in  the  nature  of  intermediate  cuttings. 
With  many  small  areas  of  different  aged  trees  within  the 
same  stand,  there  may  be  need  for  all  kinds  of  intermediate 
cuttings  simultaneously  and  in  addition  to  the  reproduction 
cuttings  which  are  annually  or  periodically  made.  Repro- 
duction and  intermediate  cuttings  within  the  same  stand  are 
thus  combined  in  one  operation,  although  each  class  of  cut- 
ting will  be  on  a  different  portion  of  the  area. 

Thinnings,  improvement  cuttings  and  salvage  cuttings  are 
the  principal  kinds  of  intermediate  cuttings  likely  to  be  made 
in  unevenaged  stands.  Cleanings  and  liberation  cuttings  find 
less  frequent  application. 

Cleanings.  —  Cuttings  made  in  young  stands  (not  past  the 
sapling  stage)  for  the  purpose  of  freeing  the  more  promising 
trees  from  other  individuals  of  similar  age  but  of  undesirable 
form  or  species  which  are  overtopping  or  are  likely  to  overtop 
the  former  trees. 

The  principal  purpose  is  to  regulate  the  mixture  to  the 
advantage  of  the  better  species  in  the  stand.  In  young 
growth  composed  entirely  of  one  species,  no  question  of 
regulating  the  mixture  arises  and  cleanings  are  not  so  essen- 


CLEANINGS  145 

tial.  If  cleanings  are  made  at  all  in  such  stands,  the  object 
is  to  remove  trees  of  poorer  form  than  those  that  are  being 
overtopped.     (See  Figs.  51  and  52.) 


Fig.  51. 

A  stand  of  white  pine  and  mixed  hardwoods  in  need  of  a  cleaning.  The 
hardwoods  and  the  large  pine,  which  is  too  limby  to  make  good  timber,  should 
be  cut.     See  Fig.  52. 

Fig.  52. 

Same  stand  as  in  Fig.  51,  but  immediately  after  the  cleaning  has  been  made. 
This  cleaning  was  made  early  enough  in  life  so  that  the  pine  had  not  yet  been 
deformed  by  the  overtopping  hardwoods.  The  operation  results  in  transform- 
ing the  stand  from  one  dominated  by  inferior  hardwoods  to  pure  pine. 

Cleanings  are  the  first  cuttings  made  in  a  new  stand  after 
its  establishment  and  should  take  place  as  soon  as  the  indi- 
viduals which  it  is  desired  to  help  are  threatened  with  injury. 
This  rarely  happens  before  the  third  or  later  than  the  tenth 
year.  For  a  few  years  the  shade  afforded  by  undesirable 
species  may  be  of  benefit  to  the  small  seedlings  of  the  more 
valuable  species  as  a  protective  cover.  The  situation  soon 
changes  and  instead  of  being  a  benefit  the  overtopping 
growth  usurps  the  growing  space,  hinders  the  growth  and, 
if  allowed  to  remain,  may  cause  the  death  of  the  better  trees. 
(See  Fig.  53.)  Sometimes  one  cleaning  is  sufficient  to  regulate 
the  mixture.  More  often  two  or  three  cuttings  made  at  in- 
tervals of  three  to  five  years  will  be  required  to  accomplish 
the  purpose.     This  is  especially  the  case  when  the  trees  re- 


146 


INTERMEDIATE   CUTTINGS 


moved  possess  sprouting  ability.     Trees  taJcenjoutm  cleanings 
belong  to  all  four  crown  classes  but  principally  to  the  domi- 


FiG.  53. 

The  same  stand  as  in  Fig.  51.  The  diagram  shows  the  relative  position  of  the 
pine  and  hardwoods  40  years  later  than  the  time  of  Fig.  51,  provided  no  cleaning 
is  made.  Note  that  only  one  pine,  namely  the  one  which  had  a  start  over  the 
hardwoods  is  now  in  a  dominant  position.  The  yield  of  this  stand  is  principally 
cordwood  instead  of  pine  lumber,  which  could  have  been  the  chief  product  if  a 
cleaning  had  been  made.    The  pines  are  indicated  by  cross-hatching. 

nant  and  co-dominant  classes.  Their  removal  creates  small 
gaps  in  the  upper  canopy.  Any  openings  of  this  character 
are  quickly  filled  by  the  better  trees  coming  up  from  beneath 
or  expanding  their  crowns. 

Specifically  the  material  removed  in  cleanings  consists  of: 

Trees  of  undesirable  species. 

Sprouts  of  a  desirable  species  if  seedlings  of  the  same 
species  can  thereby  be  freed. 

Advance  growth  of  a  desirable  species  if  inferior  in  form 
to  another  individual  of  the  same  species  which  might 
thereby  be  freed.  Scattered  trees  a  few  years  older  than 
the  remainder  of  the  stand  because  of  their  comparative 
freedom  from  side  crowding  have  rather  branchy 
crowns  and  will  not  develop  into  high  grade  trees. 


CLEANINGS 


147 


Shrubs  and  vines.  CUmbing  vines/  both  by  overtopping 
and  by  mechanically  constricting  and  deforming  trees, 
often  prove  as  serious  as  competing  tree  species. 

Several  methods  of  making  a  cleaning  may  be  employed. 
(See  Fig.  54.)  In  the  first  the  material  to  be  removed  is  cut 
down  fairly  low  to  the  ground  in  the  usual  manner.     With 


Fig. 


54- 


Various  methods  of  eliminating  the  competition  of  undesirable  trees  in  making 
a  cleaning. 

A.  Lopping  off  the  top.     This  should  be  done  at  a  point  below  the  level  of 

the  top  of  the  trees  to  be  freed. 

B.  Bending  over. 

C.  Cutting  off  at  the  base. 

D.  Cutting  off  at  the  base  of  all  trees,  except  one,  on  a  clump  of  sprouts. 

This  keeps  the  subsequent  growth  of  the  sprouts  in  check  better  than 
when  all  the  trees  in  a  clump  are  cut. 

species  which  do  not  sprout  this  method  is  fully  satisfactory. 
If  the  tree  has  sprouting  abihty,  strong  sprouts  shoot  up  from 
the  stumps  and  within  a  year  after  the  cutting  may  again 
overtop  the  valuable  species.  The  shade  and  competition  of 
the  undesirable  species  may  be  more  oppressive  than  before 
the  cutting.  To  avoid  this  other  methods  of  cutting  may  be 
used. 

In  mixed  stands  of  scrub  oak  and  other  hardwoods  under- 
planted  with  pine,  experiments  have  been  tried  of  cutting  the 


148  INTERI^IEDIATE  CUTTINGS 

hardwoods  with  the  exception  of  one  sprout  on  a  stool. ^ 
The  single  sprout  left  retarded  the  development  of  a  heavy 
sprout  reproduction  following  the  cleaning;  on  the  whole  the 
pine  was  left  in  better  condition  where  this  plan  was  used 
than  when  similar  areas  were  cut  clean. 

If  the  trees  to  be  freed  are  at  the  time  of  making  the  clean- 
ing several  feet  high  (three  to  six  feet  for  certain  species  is 
the  height  under  tliis  plan),  the  trees  removed  instead  of 
being  cut  near  the  ground  may  be  either: 

Lopped  off  so  that  they  stand  a  few  feet  lower  than  the 
top  of  the  valuable  species  and  yet  a  few  feet  above 
the  ground,  or  bent  over  with  the  top  partially  broken 
off  at  the  same  relative  height  as  in  the  first  case. 

The  new  shoots  which  arise  from  the  lopped  off  or  bent 
over  tops  have  not  the  vigor  and  rate  of  height  growth  of  the 
sprouts  starting  from  a  low  stump. 

The  relative  heights  and  rate  of  growth  of  the  trees  to  be 
favored  and  those  to  be  cut  must  be  considered  in  deciding 
upon  the  best  method  of  making  the  cleaning. 

A  cardinal  principle  in  making  cleanings  is  never  to  cut 
more  than  is  necessary  to  accompHsh  the  purpose  sought. 
Undesirable  species  should  be  cut  only  where  threatening  the 
health  of  better  trees.  Otherwise  large  and  possibly  perma- 
nent openings  might  be  created  because  some  of  the  unde- 
sirable trees  are  frequently  needed  during  the  first  part  of  the 
rotation  to  complete  the  density  of  a  stand  partially  stocked 
with  valuable  species.  The  item  of  cost  is  an  additional 
factor  rendering  it  advisable  to  restrict  the  amount  of  mate- 
rial removed  in  cleanings  to  the  minimum. 

The  small  size  of  the  material  taken  out  results  in  making 
a  cleaning  an  operation  which  is  a  source  of  immediate  ex- 
pense, returning  a  profit  only  at  some  future  time  through  an 


LIBERATION   CUTTINGS  149 

increased  yield  of  the  valuable  species  freed.  In  exceptional 
cases  where  the  material  removed  is  large  enough  for  cord- 
wood  a  cleaning  will  yield  a  small  profit.  Actual  costs  of 
making  cleanings  will  range  from  a  fraction  of  a  day's  labor 
per  acre  up  to  several  days.^  Rarely  can  a  cleaning  be  made 
for  less  than  50  cents  per  acre.  An  expenditure  of  more  than 
$10  per  acre  for  cleanings  should  receive  careful  considera- 
tion. For  freeing  white  pine  planted  on  cut-over  hardwood 
land,  two  cleanings  in  the  third  and  sixth  years  after  plant- 
ing and  requiring  altogether  from  less  than  one  to  two  days' 
labor  per  acre  are  considered  necessary  and  justified  by  the 
benefits  to  be  secured.  In  every  case  the  increased  net  re- 
turns to  be  obtained  as  a  result  of  the  cleanings  should  be 
investigated  before  such  cuttings  are  made.  Cleanings  usu- 
ally can  be  justified  where  there  is  a  wide  difference  in 
value  of  final  product  between  the  trees  freed  and  those  cut 
and  where  the  yield  of  the  valuable  species  will  be  greatly 
reduced  if  nothing  is  done.  Plantations  of  conifers  interfered 
with  by  hardwood  growth  furnish  an  excellent  illustration  of 
this  principle. 

A  variety  of  tools  will  be  found  useful  in  making  cleanings. 
The  size  of  the  material,  method  of  making  the  cuttings  and 
available  room  for  using  various  tools  should  determine  the 
selection.  The  axe  is  the  best  tool  where  the  material  is 
large  enough  for  cordwood.  In  small  brush,  bushhooks,  bill- 
hooks and  heavy  knives  of  the  machete  type  can  be  employed 
to  advantage. 

Liberation  Cuttings.  —  Cuttings  made  in  immature  stands 
for  the  purpose  of  freeing  the  young  growth  from  older  indi- 
viduals (wolf  trees)  which  are  overtopping.  Liberation  cut- 
tings are  made  during  the  same  period  in  the  life  of  the  stand 
as  are  cleanings,  but  differ  in  that  the  former  extend  in  appli- 
cation into  middle  age  and  take  out  trees  larger  and  older 


I50  INTERMEDIATE   CUTTINGS 

than  the  young  stand  while  the  latter  remove  trees  of  approxi- 
mately the  same  age  as  those  freed.  The  trees  removed  in  a 
liberation  cutting  are  either  individuals  which  were  left  stand- 
ing when  the  previous  stand  was  harvested,  or  (on  open  lands 
which  have  been  reforested)  trees  which  started  by  natural 
means  on  the  area  long  before  it  was  reforested. 

Trees  which  have  developed  with  abundant  room  on  open 
lands  are  short  and  stocky  in  character  with  short  clear  length 
and  a  wide  spreading  crown;  in  other  words  wolf  trees.  Those 
left  from  previous  cuttings  while  less  spreading  in  habit  are 
likely  to  be  cull  trees  which  it  was  unprofitable  to  cut.  Trees 
of  this  character  should  not  be  confused  with  thrifty  reserves 
which  may  have  been  left  in  the  reproduction  cuttings  to 
grow  through  a  second  rotation. 

Liberation  cuttings  should  be  made  as  early  in  the  life  of 
the  young  stand  as  possible.  The  shade  and  protection  of 
these  large  trees  soon  ceases  to  be  beneficial.  If  left  too  long, 
death  of  all  the  overtopped  young  trees  may  result.  Less 
damage  is  caused  to  the  young  growth  and  less  expense  is 
involved  in  the  removal  of  the  large  trees  if  the  operation  is 
accomphshed  when  the  young  stand  is  only  a  foot  or  two  in 
height.  Where  the  operation  has  been  delayed  until  the  young 
trees  are  pressing  with  their  crowns  against  the  crowns  of  the 
overtopping  trees  and  bending  aside  for  light  the  result  of 
the  cutting  is  less  satisfactory.  (See  Figs.  55  and  56.)  In  the 
latter  case  it  is  possible  that  gaps  large  enough  to  require 
filhng  by  artificial  means  may  be  created  by  the  competition  of 
the  large  trees  and  through  damage  inflicted  in  this  removal. 

The  ordinary  practice  in  making  liberation  cuttings  is  to 
fell  the  trees,  and  utihze  whatever  merchantable  material 
they  contain.  Care  must  be  taken  to  cut  up  the  tops  and 
place  them  in  such  position  as  not  to  interfere  with  the  young 
growth. 


LIBERATION  CUTTINGS 


151 


Another  method  employed  is  to  girdle,  but  leave  standing, 
the  overtopping  trees.  Cutting  a  ring  around  the  trunk 
through  the  bark  and  well  into  the  sapwood  will  cause  death 


(^^$^^;^?;^!?;^s^vv^^ 


Reproduction 


Fig.  55. 
A  stand  in  need  of  a  liberation  cutting. 


„.    The  young  trees  as  yet  have  not  been 

seriously  affected  by  the  large  overtopping  trees. 


mm 


Fig.  56. 

A  stand  in  need  of  a  liberation  cutting.    The  cutting  should  have  been  made 
20  years  ago  before  the  young  trees  under  the  old  ones  had  been  deformed. 


of  the  tree.  Some  species  are  harder  to  kill  by  girdling  than 
others  and  the  details  of  performing  the  operation  should  be 
varied  to  suit  the  conditions.  The  advantages  of  girdling  are 
its  cheapness  and  avoidance  of  damage  to  the  young  growth 


152  INTERMEDIATE  CUTTINGS 

in  felling.  As  the  trees  decay  and  fall  to  pieces  some  injury 
may  be  done  to  the  young  growth  but  far  less  than  that 
caused  by  felling  the  trees.  Girdling  is  particularly  useful 
where  the  value  of  the  material  in  the  large  trees  is  less  than 
the  cost  of  removal. 

Whether  an  immediate  money  return  can  be  secured  from  a 
liberation  cutting  cannot  be  predicted  without  a  careful  in- 
spection of  the  overtopping  trees  and  the  difficulties  attending 
their  removal.  Cordwood  of  good  size  is  ordinarily  one  of  the 
chief  products  and  some  of  the  trees  may  contain  one  or  more 
logs  merchantable  for  lumber.  The  expense  of  cutting  up 
the  branchy  trees  and  bringing  together  the  logs  and  wood 
sparsely  scattered  over  an  area  occupied  by  young  growth  is 
so  high  as  to  seriously  cut  into  the  revenue  received  from  the 
logs  and  wood.  Unless  cutting  and  taking  out  the  merchant- 
able material  will  at  least  pay  all  expenses  of  the  work,  gird- 
ling should  be  employed.  This,  although  involving  a  small 
money  outlay,  will  be  found  advisable  in  most  cases  on 
account  of  increased  future  yield. 

REFERENCES 

1.  Illick,  J.  S.  Preliminary  Report  of  Some  Forest  Experiments  in  Penn- 
sylvania.    Journal  of  Forestry,  Vol.  XVII,  1919,  pp.  304-311. 

2.  Sterrett,  W.  D.  Disengagement  Cuttings  in  Mixed  Small  Sapling 
Stands.     Forestry  Quarterly,  Vol.  XI,  1913,  pp.  62-63. 

3.  Fisher,  R.  T.  The  Yield  of  Volunteer  Growth  as  Affected  by  Improve- 
ment Cutting  and  Early  Weeding.     Journal  of  Forestry,  Vol.  16,  1918,  p.  503. 

4.  TiLLOTSON,  C.  R.  The  Care  and  Improvement  of  the  Wood  Lot. 
Farmers  Bulletin  711,  United  States  Department  of  Agriculture,  Washington, 
1916,  p.  12. 

5.  Fisher,  R.  T.,  and  Terry,  E.  I.  The  Management  of  Second  Growth 
White  Pine  in  Central  New  England.  Journal  of  Forestry,  Vol.  18,  1920,  pp. 
364-365. 


CHAPTER  X 
INTERMEDIATE  CUTTINGS    (Continued).     THINNINGS 

Cuttings  made  in  immature  stands  for  the  purpose  of 
increasing  the  rate  of  growth  of  the  trees  that  remain  and 
the  total  production  of  the  stand  are  termed  thinnings. 

Natural  Development  of  the  Stand.  —  The  theory  of  mak- 
ing thinnings  finds  its  basis  in  the  natural  process  of  develop- 
ment of  the  stand.  The  average  stand  starts  Kfe  with  a 
relatively  large  number  (usually  expressed  in  the  thousands 
or  even  tens  of  thousands)  of  trees  per  acre.  At  the  end  of 
its  life,  when  ready  for  the  reproduction  cuttings,  the  number 
has  been  reduced  to  a  few  hundred  trees  per  acre  —  sometimes 
less  than  loo.     (See  Fig.  57.) 

Ruthless  competition  for  light,  growing  space,  moisture 
and  nourishment  has  accompHshed  this  diminution  in  num- 
bers. The  individual  trees  which  survive  are  well  pruned  of 
branches  and  contain  a  high  percentage  of  clear  lumber,  but 
among  them  there  are  apt  to  be  individuals  of  undesirable 
species  or  of  poor  form. 

The  struggle  for  existence  may  have  been  so  fierce  as  to 
reduce  the  diameter  and  height  growth.  The  competition 
between  the  trees  is  well  expressed  by  the  changes  in  relative 
position  in  the  crown  cover  which  are  in  constant  progress. 
As  the  weaker  trees  are  crowded  by  their  associates  their 
crowns  are  restricted  and  forced  out  of  the  normal  shape, 
they  bend  aside  seeking  for  light,  are  finally  overtopped  and 
ultimately  die.  It  is  a  steady  progression  downward  which 
only  the  strongest  are  able  to  escape.  This  differentiation  is 
153 


154 


INTERMEDIATE   CUTTINGS  —  THINNINGS 


technically  known  as  a  differentiation  into  crown  classes  and 
standard  crown  classes  are  recognized.  (See  Figs.  58  and  59.) 
Classification  into  Crown  Classes.  —  The  classification  here- 
with given  is  that  favored  by  the  Society  of  American  For- 
esters.    See  Appendix. 

3000 


2700 


2400 


o  2100 


p^  1800 


S  1200 

a 

g  900 


\ 

\ 

\ 

\, 

\ 

v\ 

\ 

p 

V 

\J 

1 

1 

^ 

\* 

-^ 

■ — 

— 

10 


20 


30 


50  60 
in  Years 
Bulletin  13, 


70 


80 


90 


100 


40 

Age 

X  Curve  plotted  from  data  on  p.  21,  Bulletin  13,  United  States  Department 
of  Agriculture,  entitled  "  White  Pine  under  Forest  Management". 

fi:  Curve  plotted  from  data  on  p.  41,  Bulletin  244,  United  States  Department 
of  Agriculture,  entitled  "  Life  History  of  Shortleaf  Pine". 

*  Curve  plotted  from  data  on  p.  24,  Bulletin  24,  United  States  Department 
of  Agriculture,  entitled  "  Cottonwood  in  the  Mississippi  Valley". 

Fig.  57. 
Curves  showing  the  reduction  in  number  of  trees  per  acre  due  to  natural 
causes  with  increase  of  age  for  stands  of  cotton  wood,  shortleaf  pine  and  white 
pine  on  Quality  I  soils. 


STANDARD   CROWN  CLASSES 


155 


Standard  Crown  Classes 
Dominant.  —  Trees  with  crowns  extending  above  the  gen- 
eral level  of  the  forest  canopy  and  receiving  full  Hght  from 
above  and  partly  from  the  side;  larger  than  the  average  trees 

D  =  Dominant  trees.         C-D  =  Co-Dominant  trees.  I  =  Intermediate  trees. 

Op  =  Oppressed  trees.        S  =  Suppressed  trees. 


Fig.  58. 
Illustrates  the  relative  position  of  trees  of  the  different  crown  classes. 


Fig.  59. 
Illustrates  the  passing  of  trees  from  the  dominant  down  to  the  suppressed 
crown  class  with  advancing  age,  as  a  result  of  the  struggle  for  existence.     The 
letters  indicate  the  crown  classes  of  the  trees. 


156  INTERMEDIATE   CUTTINGS  —  THINNINGS 

in  the  stand,  and  with  crowns  well-developed  but  possibly 
somewhat  crowded  on  the  sides. 

Co-dominant.  —  Trees  with  crowns  forming  the  general  level 
of  the  forest  canopy  and  receiving  full  hght  from  above  but 
comparatively  little  from  the  sides;  usually  with  medium- 
sized  crowns  considerably  crowded  on  the  sides. 

Intermediate.  —  Trees  with  crowns  below,  but  still  extend- 
ing into,  the  general  level  of  the  forest  canopy,  receiving 
a  little  direct  light  from  above  but  none  from  the  sides; 
usually  with  small  crowns  considerably  crowded  on  the  sides. 

Overtopped.  —  Trees  with  crowns  entirely  below  the  gen- 
eral forest  canopy  and  receiving  no  direct  light  either  from 
above  or  from  the   sides.     These  may  be  further  divided 

Oppressed.  —  Usually  with  small  poorly  developed 
crowns  still  aHve,  and  possibly  able  to  recover,  and 
Suppressed,  or  dying  and  dead. 

The  silviculturist,  while  recognizing  the  value  of  the  strug- 
gle for  existence  in  assisting  the  production  of  lumber  free 
from  knots,  attempts  by  making  thinnings,  to  avoid  its  dis- 
advantages of  lessened  production  and  inclusion  of  undesirable 
species  and  trees  of  poor  form  in  the  final  stand. 

Advantages  of  Thinnings.  —  The  advantages  of  thinnings 
applied  in  the  stand  as  compared  with  Nature's  unrestricted 
competition  can  be  summed  up  under  the  following  headings: 

iQThe  length  of  time  required  to  grow  products  of  the 
desired  sizes  can  be  shortened  by  the  use  of  thinnings.)  This 
is  accomplished  through  an  increase  in  both  diameter  and 
height  growth  coming  as  a  consequence  of  eliminating  strong 
competition  between  individual  trees.  The  trees  remaining 
after  the  thinning  have  room  to  expand  their  crowns  and 
root  systems  and  secure  large  supplies  of  food,  instead  of 
fighting  with  numerous  associates  for  part  of  the  same  total. 


ADVANTAGES  OF  THINNINGS  157 

The  productive  energy  of  the  site  is  thus  utilized  by  a  smaller 
number  of  trees  which  are  thereby  enabled  to  attain  a  given 
size  more  quickly.  It  should  be  emphasized  that  not  only  is 
diameter  growth  increased  but  also  to  a  lesser  extent  growth 
in  height.  The  popular  idea  that  height  growth  is  directly 
dependent  upon,  and  increases  with  the  density  of  the  stand 
is  unsound.  Height  growth  will  be  greatest  when  the  trees 
are  kept  in  the  vigorous  condition  found  in  the  properly 
thinned  stand.^ 

The  actual  crown  surface  exposed  to  direct  sunlight  is 
greater  in  the  thinned  than  in  the  unthinned  stand,  making 
possible  faster  growth.  In  the  latter  the  crowns  of  the  trees 
interlace  with  a  relatively  level  top  surface  exposed  to  the 
sun  with  only  occasional  dominant  trees  raising  a  portion  of 
their  crown  above  the  general  level.  After  a  thinning  cup- 
like depressions  exist  between  the  individual  trees  allowing 
direct  light  to  reach  the  sides  as  well  as  the  tops  of  the 
crowns.  Thus  the  crown  area  receiving  direct  light  is  greater. 
(See  Fig.  60.) 

Profile  of  Crowns  on  a 
Section  through  aa 
Unthinned  Stand 


Exoffle  of  Crowns  on  a 
Section  through  a 
Thinned  Stand 


Fig.  60. 
Profiles  of  tree  crowns  on  sections  through  unthinned  and  thinned  stands. 

2.  Thinnings  raise  the  quaHty  of  the  product  composing 
the  final  crop.  Trees  of  poor  form,  those  containing  defects 
or  of  relatively  inferior  species  can  be  taken  out  and  the  few 
best  trees  left  upon  which  growth  will  be  concentrated. 


158  INTERMEDIATE   CUTTINGS  —  THINNINGS 

The  larger  diameters,  and  hence  widths  of  lumber,  obtain- 
able from  thinned  stands  heighten  the  value  of  the  product. 
Greater  crown  development  following  the  opening  up  of  the 
stand  by  a  thinning  does  not  reduce  the  clear  length  of  the 
trees.  In  fact  although  the  crown  may  be  lengthened  by 
thinnings  yet  greater  clear  lengths  may  be  produced  on  account 
of  the  greater  total  height  in  the  thinned  stand .^ 

3.  By  thinnings  the  total  yield  both  in  quantity  and  in  value 
of  product  secured  from  a  given  area  in  a  specified  period  will 
be  increased.     Various  factors  contribute  to  this  result. 

Thinnings  remove  and  utilize  principally  trees  which  in  the 
unthinned  stand  die  in  the  struggle  for  existence  and  decay 
before  the  crop  is  harvested.  As  thinnings  can  be  applied 
so  as  to  increase  the  total  quantity  secured  from  thinnings 
and  reproduction  cuttings  combined  during  a  given  period 
from  50  to  100  per  cent  above  the  final  3deld  of  an  unthinned 
stand  the  saving  in  amount  of  product  is  considerable. 

The  yield  is  increased  in  value  for  the  reasons: 

First,  a  higher  quality  of  product  is  produced  as  explained 
under  heading  2. 

Second,  the  thinnings  furnish  financial  returns  compara- 
tively early  in  the  rotation.  With  a  timber  crop  which  re- 
quires a  long  time  to  mature  the  time  element  involving  com- 
pound interest  charges  is  a  vital  factor  in  determining  costs 
of  product  on.     Early  returns  mean  higher  profits. 

Third,  the  shorter  rotation  within  which  the  same  sized 
products  can  be  grown  as  on  a  longer  rotation  in  the  unthinned 
stand  has  a  favorable  influence  on  the  financial  result  similar 
to  that  exerted  by  the  early  returns  from  the  thinnings. 

4.  Stands  may  be  made  more  resistant  to  windthrow  and 
breakage  by  ice,  snow  and  wind  if  thinned.  The  expansion 
of  the  crown  and  root  system  following  a  thinning  increases 
the  power  of  a  tree  to  withstand  these  agencies.     A  slender 


TIME  TO  START  THIx^NINGS  1 59 

weak  tree  cannot  quickly  be  converted  into  a  resistant  indi- 
vidual by  one  cutting.  The  change  must  come  gradually. 
If  a  weak  tree  is  too  suddenly  left  unsupported  the  thinning 
may  result  in  its  being  broken  or  overthrown. 

5.  Thinnings  keep  the  stand  free  of  unhealthy  and  dying 
trees  in  which  insects  and  fungi  find  the  best  opportunities 
for  development.  The  trees  remaining  in  a  stand  systemati- 
cally thinned,  being  exceptionally  thrifty,  do  not  succumb  to 
the  attacks  of  insects  and  fungi  as  easily  as  do  the  weaker 
trees  in  unthinned  stands. 

Time  to  Start  Thinnings.  —  Theoretically  thinnings  are 
needed  just  as  soon  as  the  struggle  for  existence  between  the 
trees  in  a  stand  has  become  serious.  This  condition  may 
arise  within  a  few  years  after  establishment  in  a  densely 
stocked  stand  and  is  rarely  deferred  later  than  the  tenth  to 
fifteenth  years.  The  density  of  stocking,  productive  power  of 
the  site^and  the  spreading  habit  of  the  species  determine  the 
time  for  making  the  first  thinning.  The  item  of  expense  also 
should  be  considered.  In  young  stands  the  material  removed 
may  not  be  valuable  enough  to  pay  the  cost  of  the  operation. 
A  general  rule  is  not  to  make  the  first  thinning  until  the  re- 
ceipts will  at  least  pay  the  expenses. 

The  life  history  of  an  evenaged  stand  may  be  divided  into 
three  stages  from  the  establishment  of  the  crop  to  the  begin- 
ning of  the  regeneration  period. 

The  first  lasts  so  long  as  there  is  not  a  marked  differentia- 
tion between  individual  trees.  Its  duration  is  brief  and  no 
intermediate  cuttings,  with  the  possible  exception  of  a  libera- 
tion cutting,  are  needed.  The  second  begins  with  the  differ- 
entiation into  crown  classes  and  is  characterized  as  the  period 
of  height  growth.  This  lasts  for  one  to  two  decades  during 
the  early  part  of  which  cleanings  to  regulate  the  composition 
are  required.     In  the  latter  part  of  the  period  an  early  thin- 


l6o  INTERMEDIATE   CUTTINGS  —  THINNINGS 

ning  may  be  desirable  in  dense  stands.  During  this  period 
the  tendency  of  the  trees  to  expand  laterally  is  not  great  and 
hence  the  loss  of  growth  through  keeping  the  stand  dense  is 
small. 

The  third  stage  begins  when  the  trees  in  the  stand  show  a 
strong  tendency  for  lateral  development.  It  is  the  longest 
period  of  the  three  and  thinnings  to  increase  the  growth  of 
the  trees  and  the  yield  of  the  stand  are  demanded.  In  this 
stage  the  trees  are  capable  after  thinnings  of  increasing 
largely  their  rate  of  growth. 

It  is  possible  for  a  stand  in  need  of  a  thinning  to  remain  so 
long  unthinned  that  it  fails  to  respond  when  finally  such  a 
cutting  is  made.  In  a  case  of  this  kind  the  competition  has 
continued  so  long  and  fiercely  and  the  struggle  between  the 
individuals  has  been  so  even  that  diameter  and  height  growth 
have  suffered  and  the  crowns,  even  of  the  dominant  trees,  have 
been  reduced  to  small  tufts  at  the  tops  of  weak  slender  stems. 
After  a  thinning  in  such  a  stand  the  trees  left  are  apt  to  suffer 
from  drought,  sunscald  and  insect  attacks,  be  thrown  or 
broken  by  wind  and  have  apparently  lost  the  ability  to 
respond  with  increased  growth.  Stands  densely  stocked, 
growing  on  poor  soil,  are  the  ones  most  hkely  to  be  in  this 
condition.  The  appearance  of  the  crowns  and  boles,  particu- 
larly the  length  of  crown  in  relation  to  the  total  height  of  the 
tree,  is  the  best  indication  of  whether  a  stand  has  gone  un- 
thinned so  long  as  to  be  incapable  of  profiting  by  a  thinning. 

Methods  of  Making  Thinnings.  —  From  what  has  been  said 
previously,  it  will  be  evident  that  the  relative  position  of  the 
crowns  of  the  trees  is  of  primary  importance  in  determining 
which  trees  should  be  removed  and  which  left.  The  thinning 
must  provide  opportunity  for  expansion  of  the  crowns  and 
root  systems  of  the  trees  left  and  must  see  that  sufficient  crown 
spread  remains  to  fully  stock  the  area.     Crown  classes  furnish 


METHODS   OF  MAKING  THINNINGS  l6l 

the  principal  basis  for  cutting  or  leaving  a  tree  and  the  rela- 
tive position  of  the  crown  of  each  tree  must  be  observed  with 
respect  to  its  associates.  The  distribution  over  the  area  of  the 
trunks  of  the  trees  is  not  so  important  because  this  may  not 
coincide  with  position  of  the  crowns. 

The  highest  production  as  a  result  of  thinnings  can  only 
be  secured  by  leaving  the  largest  number  of  trees  per  acre 
consistent  with  rapid  growth  of  the  individual.  The  indi- 
vidual tree  may  grow  fastest  out  in  the  open,  entirely  iso- 
lated, but  this  would  result  in  a  low  production  per  acre 
because  the  area  would  be  only  partially  stocked.  It  is 
necessary  to  determine  the  minimum  amount  of  growing 
space  which  the  tree  demands  for  fast  growth  and  then  keep 
the  largest  number  of  trees  properly  distributed  over  each 
acre  which  this  growing  space  admits.  As  the  stand  grows 
older,  the  number  of  trees  per  acre  must  decrease  because  the 
crown  space  required  by  each  tree  is  steadily  enlarging;  but 
the  total  area  occupied  by  the  crown  canopy  should  remain 
approximately  the  same.  Quick  and  accurate  measurement 
of  the  crown  spread  of  the  trees  on  a  given  area  is  difl&cult  but 
the  basal  (sectional)  area  at  breast-high  is  easily  measured 
and  can  be  safely  substituted  as'  an  expression  for  the  total 
crown  spread.* 

Using  this  idea  the  proper  basal  area  (used  as  an  indica- 
tion of  total  crown  spread  and  of  the  number  of  trees  per 
acre  at  each  age)  for  a  given  species  and  site  should  be  de- 
termined and  the  stand  kept  close  to  this  basal  area  by  thin- 
nings. "The  total  sectional  area  gives  the  best  (single)  indi- 
cation of  density,  so  much  so  that  the  extent  of  the  thinnings 

*  The  growth  in  volume  of  trees  is  dependent  upon  the  activity  of  the 
crowns  and  may  be  considered  proportional  to  the  crown  spread.  Basal  area 
may,  for  comparative  purposes,  be  used  as  an  abbreviated  expression  of  the 
volume  of  the  stand  and  for  the  purpose  stated  above  be  substituted  for  crown 
spread. 


l62  INTERMEDIATE   CUTTINGS  —  THINNINGS 

to  be  carried  out  from  time  to  time  may  be  indicated  by  the 
total  sectional  area  to  be  maintained  on  the  ground,  whereas 
this  could  never  be  done  by  number  of  trees."  ^ 

Three  distinct  ideas  in  the  method  of  making  thinnings  can 
be  recognized,  each  leading  to  a  different  selection  of  the  trees 
to  be  removed  in  a  given  stand.  All  three  base  the  selection 
of  the  trees  upon  their  crown  classifications. 

The  three  methods  may  be  termed : 

1.  The  German  or  ordinary, 

2.  The  French,  and 

3.  Borggreve's  method. 

Each  will  be  discussed  in  turn. 

The  German  or  Ordinary  Method  of  Thinning.  —  Sometimes 
termed  ''thinning  from  below." 

In  this  method  the  principle  used  is  to  take  out  the  poorest 
crown  class  (suppressed  trees)  first  and  then  to  work  upward 
in  consecutive  order  through  the  better  crown  classes  in- 
creasing the  number  of  classes  removed  with  the  severity  of 
the  thinning.  The  weakest  trees  and  those  which  must  be 
utilized  immediately  to  save  them  from  death  and  decay  are 
cut  and  as  many  more  of  the  intermediate,  co-dominant,  and 
dominant  as  the  desired  heaviness  of  the  thinning  warrants. 
All  trees  of  the  crown  class  next  lowest  would  be  cut  before 
trees  from  another  crown  class  were  taken.  After  the  heavi- 
est thinning  some  members  of  the  dominant  class  will  remain 
but  none  of  the  other  classes.  Less  severe  thinnings  leave 
representatives  of  other  crown  classes. 

Based  on  the  severity  of  the  cutting,  several  grades  of 
thinnings  are  recognized  under  the  ordinary  method:  (See 
Appendix.) 

Grade  A.  —  Light.     Removes  suppressed  trees. 

Grade  B .  —  Moderate.  Removes  in  addition  oppressed  and 
poorest  intermediate  trees. 


METHODS   OF  MAKING  THINNINGS 


163 


Grade  C.  —  Heavy.  Removes  in  addition  the  remaining 
intermediate  trees. 

Grade  D.  —  Very  heavy.  Removes  in  addition  many  of 
the  co-dominant  trees. 

Interlucation  or  accretion  cutting.  Removes  in  addition 
the  remaining  co-dominant  and  a  few  dominant  trees. 

This  classification  is  conservative.  Under  a  more  radical 
one  additional  trees  to  those  specified  might  be  removed 
under  each  of  the  various  grades.     (See  Figs.  61  to  68.) 

The  amount  removed  in  thinnings  varies  from  as  low  as 
5  per  cent  in  a  Grade  A  thinning  to  around  40  per  cent  of  the 
total  cubic  volume  in  Grade  D.  Experience  in  this  country 
is  based  upon  the  first  thinning  at  different  ages  in  stands 
previously  unmanaged. 

Tables  of  yield  in  feet,  board  measure,  from  thinnings  for 
white  pine  {Pinus  strohus)  have  been  pubHshed  by  the  For- 
estry" Commission  of  New  Hampshire  ^  and  the  State  Forester 
of  Massachusetts.^  From  these  tables  the  following  percent- 
ages have  been  calculated.  The  thinnings  approximated 
Grade  C. 


Per  Cent  of  Total  Board  Foot  Volume  Cut  in  Thinnings 


On  site  quality 

First  thinning  at 
age  of: 

I 

II 

I 

II 

Based  on  New  Hampshire  figures 

Based  on  Massachusetts  figures 

Years 

25 

9 

12 

13 

20 

30 

20 

30 

20 

30 

40 

22 

30 

15 

20 

50 

20 

25 

13 

18 

The  author  has  found  that  in  thinning  sprout  hardwood 
stands  in  Connecticut,  40  to  50  years  of  age,  a  Grade  C  thin- 


164 


i6s 


-s  2 


a  n 

a 

hr 

it) 

H 

g 

<1J 

'-' 

-S 

to 

id 

C 

m 

"? 

:2 

•Si 


cq   o 
<  .5 


.£f 

Ph 

0) 

_C 

(Si 

13 

S 

"S 

.2 

i66 


CI3 


O    ra 

•sl 

fl  a 


is 


167 


d_> 


Cs 


£ 


a;  .g 

1    o 

en   '3 

^    o 

be    <D 

c    o 


G^ 


i68 


METHODS  OF  MAKING  THINNINGS 


169 


ning  in  a  stand  on  good  soil  previously  unthinned  will  remove 
approximately  one-third  of  the  cubic  foot  volume,  while  a 
second  thinning  five  to  eight  years  after  the  first  takes  out 
20  to  25  per  cent. 

As  an  indication  of  what  may  be  obtained  when  stands  are 
repeatedly  thinned,  the  following  table  showing  the  per  cent 


Fig.  66. 

Diagram  showing  the  arrangement  of  crowns  in  a  50  year  old  hardwood 
stand  in  need  of  a  thinning.  The  crowns  of  overtopped  trees  are  indicated  by 
broken  lines.     Compare  with  Figs.  67  and  68. 


of  the  total  cubic  foot  volume  removed  in  thinnings  has  been 
prepared  from  yield  tables  given  in  Schhch's^  Manual  of 
Forestry  and  secured  by  him  from  the  original  tables  com- 
piled by  Wimmenauer  for  oak  and  Schwappach  for  pine. 


170 


INTERMEDIATE   CUTTINGS  —  THINNINGS 


Per  Cent  of  Total  Cubic  Foot  Volume  Removed  in  Thinnings 


Age 

Oak 

Pine 

I 

III 

I 

III 

Years 

30 
40 

io 

70 
80 
90 
100 

15 
12 
10 

7 
7 
6 

IS 
13 
II 

9 

6 
6 

14 
15 
14 
II 

7 
6 
5 
5 

6 
S 
4 
4 
3 
3 

Fig.  67. 

The  same  stand  as  shown  in  Fig.  66,  but  after  an  A  grade  thinning  removing 
suppressed  trees  has  been  made.  Note  that  the  main  crown  canopy  has  not 
been  opened  by  this  Hght  thinning.     Compare  with  Fig.  68. 


METHODS   OF  MAKING  THINNINGS  171 

Interlucation  or  Accretion  Cuttings.  —  Accretion  cuttings  are 
classed  as  the  heaviest  grade  of  thinnings  and  like  other  thin- 
nings are  not  intended  to  make  permanent  gaps  in  the  cover. 
Their  purpose  is  to  obtain  exceptionally  rapid  diameter  growth 
of   individual    trees,  not   attainable  with  lighter  thinnings. 


Fig. 

The  same  stand  as  shown  in  Fig.  66,  but  immediately  after  a  D  grade  thinning, 
removing  overtopped,  intermediate  and  many  co-dominant  trees.  Note  that 
the  crown  canopy  has  been  opened  and  every  one  of  the  remaining  trees  given 
increased  room  on  one  or  more  sides.     Compare  with  Figs.  67  and  77. 

They  are  needed  particularly  with  light  demanding  species, 
for  shade  enduring  trees  grow  rapidly  following  lighter  thin- 
nings. In  making  accretion  cuttings  there  is  great  danger  of 
reducing  the  volume  production  per  acre,  although  the  in- 
creased value  of  the  large  trees  may  offset  financially  any  such 
reduction. 


172  INTERMEDIATE   CUTTINGS  —  THINNINGS 

Light  demanding  species  with  thin  foliage  may  form  nearly  a 
complete  canopy  with  their  crowns  and  still  allow  so  much 
light  to  reach  the  ground  that  the  soil  may  deteriorate  or  an 
undesirable  growth  of  grass,  weeds  or  underbrush  start.  An 
understory  is  needed  to  protect  the  site  whenever  accretion 
cuttings  are  made  in  a  stand  of  thin  fohaged  trees.  Such  an 
understory  may  be  established  by  natural  or  artificial  means. 

Accretion  cuttings  should  be  used_only  in  the  latter  half  of 
relatively  short  rotations  on  soils  where  there  are  abundant 
moisture  and  food  materials  available  for  increased  growth 
and  where  an  understory  can  be  developed  naturally  or 
artificially  for  a  small  expenditure. 

A  distinction  should  be  made  between  accretion  cuttings® 
used  as  intermediate  cuttings  and  hence  keeping  the  cover 
close  enough  to  utilize  completely  the  productive  power  of  the 
site,  and  cuttings  of  a  similar  nature  which  permanently  break 
the  cover  and  are  essentially  reproduction  cuttings  started 
early  in  order  to  secure  increased  growth  on  selected  trees. 

Nisbit^  states  that  any  thinning  which  removes  over  15 
per  cent  of  the  total  basal  area  is  an  accretion  cutting. 

The  French  Method.^  —  ("  Eclaircie  par  le  haut  "  or  "  thin- 
nings from  above.") 

Under  the  French  method,  so  called,  every  opportunity  for 
rapid  growth  is  given  to  certain  of  the  best  dominant  trees 
by  completely  freeing  them  from  competition  comparatively 
early  in  the  rotation.  As  compared  with  the  ordinary  method 
a  thinning  similar  to  Grade  D  or  heavier  is  made  in  the  inter- 
mediate, co-dominant  and  dominant  crown  classes,  while  the 
overtopped  trees  are  allowed  to  remain  except  for  a  Grade  A 
thinning  which  removes  the  suppressed  trees.  (See  Figs.  69 
and  70.) 

In  starting  the  French  method  a  number  of  trees,  sufficient 
to  stock  the  area  at  maturity  and  distributed  as  uniformly  as 


173 


H    ^ 


.   B 

hn    O 


•g  .S 


a  2 


R 

o 

pi 

1 

^ 

I  cro 
died 
they 

rt          +j 

.s 

IS 

the  fi 
d   hav 
ote  th 

1 

■5  3  Z 

rfering 
which 
Itching 

.  s  ^ 


OJ       OJ 


METHODS   OF  MAKING  THINNINGS  175 

possible,  are  selected  from  among  the  best  dominant  trees. 
After  the  selection  of  the  final  crop  trees  has  been  accom- 
plished a  heavy  thinning  is  made,  taking  out  all  trees  of  any 
crown  class  which  are  interfering  with  the  development  of 
the  final  crop  trees.  Such  a  cutting  frequently  involves  the 
removal  of  dominant  trees  and  the  leaving  of  openings  in  the 
main  canopy  which  do  not  close  for  several  years.  To  pre- 
vent undue  exposure  of  the  site  as  a  result  of  the  heavy  thin- 
ning the  overtopped  trees  are  left  standing  to  furnish  a  pro- 
tective cover.  From  among  the  overtopped  trees  the  sup- 
pressed, i.e.,  those  already  dead  or  dying,  are  culled  in  a  light 
thinning  to  secure  utilization  before  the  trees  become  worthless. 

Where  the  final  crop  trees  stand  fairly  far  apart  the  first 
heavy  thinning,  in  accomplishing  its  purpose  of  freeing  on 
all  sides  the  selected  trees,  may  leave  dominant,  co-dominant 
or  intermediate  trees  not  interfering  for  the  present  with  the 
selected  individuals.  In  the  subsequent  thinnings  all  trees 
(not  final  crop  trees)  in  the  upper  crown  classes  would  be 
removed  leaving  eventually  only  the  final  crop  trees  with  an 
understory  composed  of  the  oppressed  class.  The  volume  re- 
moved corresponds  to  that  taken  out  in  Grade  D  under  the 
ordinary  method. 

The  advantages  of  the  French  over  the  ordinary  method 
are  that: 

(a)  Bigger  timber  can  be  produced  in  the  same  time  or 
timber  of  the  required  size  in  a  shorter  time.  This  is  made 
possible  by  the  freedom  for  expansion  afforded  the  crowns  of 
the  selected  trees.  As  individuals  they  have  more  room  than 
would  be  possible  under  the  ordinary  method  because  the 
overtopped  stand  preserves  a  close  cover  and  obviates  the 
necessity  of  the  dominant  stand  maintaining  a  complete 
canopy. 

(b)  The  method  gives  higher  immediate  cash  returns  from 


176  INTERMEDIATE  CUTTINGS  —  THINNINGS 

the  thinnings,  because  the  material  removed  averages  of 
larger  size  and  better  quality  than  in  the  ordinary  method  — 
except  for  the  heaviest  grade  of  thinning.  A  comparison  of 
the  crown  classes  removed  in  each  of  the  two  plainly  indicates 
this. 

(c)  Any  light  admitted  through  the  openings  in  the  main 
stand  is  utihzed  by  the  overtopped  trees  which  are  able  to 
continue  growth,  slowly  producing  cordwood  as  the  principal 
product.  Under  the  ordinary  method  any  light  admitted 
after  a  heavy  thinning  tends  to  stimulate  a  growth  of  grass, 
weeds  and  shrubs. 

The  principal  disadvantage  of  the  method,  but  not  a  serious 
drawback,  is  the  fact  that  the  overtopped  trees  left  standing 
are  a  hindrance  in  the  work  of  felling  and  transporting  from 
the  area  the  material  cut. 

Thinnings  according  to  the  French  method  should  not  be 
started  until  around  the  thirtieth  year  when  the  period  of 
most  rapid  height  growth  is  past  and  the  stems  have  been 
cleared  by  natural  pruning.  The  heavy  thinning  if  made 
before  natural  pruning  was  well  started  would  result  in  mak- 
ing the  final  crop  trees  too  wide  spreading  and  branchy  with 
short  clear  boles. 

The  overtopped  trees  prevent  the  production  of  epicormic 
branches  on  the  main  stems  and  continue  to  some  extent  the 
natural  pruning. 

If  the  stand  requires  thinning  before  the  French  method 
can  be  started,  a  thinning  on  the  ordinary  method  may  be 
made. 

The  French  method  can  be  applied  successfully  in  either 
pure  or  mixed  stands.  Undoubtedly  the  best  combination 
from  the  standpoint  of  the  greatest  yield  in  quantity  and 
quality  is  found  in  a  stand  where  the  final  crop  trees  are  of  a 
light  demanding  species,  while  the  overtopped  stand  is  formed 


METHODS   OF   MAKING  THINNINGS  1 77 

by  a  dense  foliaged,  shade  enduring,  species  capable  of  fur- 
nishing best  protection  to  the  site,  profiting  by  the  chance  for 
growth  in  a  shaded  position  and  functioning  efficiently  as  a 
pruner  of  the  dominant  stems. 

For  thinning  stands  of  eastern  white  pine  Fernow  ^  ad- 
vdsed  the  method  as  early  as  1903.  He  recommended  the 
selection  at  30  years  of  200  trees  to  form  the  final  crop  and 
the  freeing  of  their  crowns  by  a  thinning  for  a  space  of  two 
to  three  feet  on  all  sides.  This  would  be  repeated  as  often 
as  the  crowns  touched. 

Borggreve's  Method.  —  Borggreve  ^°  developed  a  method 
of  thinning  radically  differing  in  principle  from  either  of  the 
two  methods  already  mentioned.  His  idea  is  to  take  out 
two  classes  of  trees  in  the  thinning: 

(a)  The  largest  dominant  trees. 

(6)  The  suppressed  trees;  in  order  to  utilize  them  before 
they  become  a  total  loss. 

The  removal  of  the  suppressed  trees  constitutes  a  Grade  A 
thinning  under  the  ordinary  method,  but  taking  out  the 
largest  dominant  trees  is  directly  opposed  to  the  principles  of 
the  ordinary  or  French  methods,  which  even  in  their  heaviest 
cuttings  leave  the  very  trees  which  Borggreve  cuts  in  his 
first  thinning.  Selection  thinning  is  another  name  for  this 
style  of  thinning. 

The  selection  of  the  dominant  trees  to  be  removed  is  made 
on  the  basis  of  their  form  and  the  quaHty  of  the  timber  they 
can  eventually  produce  as  compared  with  their  associates. 
This  results  usually  in  the  cutting  of  the  largest  dominant 
trees,  for  such  trees  in  attaining  their  commanding  position 
developed  large  limbs  and  possibly  forked  trunks  which  the 
smaller  dominant,  co-dominant,  and  intermediate  trees  have 
escaped,  due  to  their  more  restricted  opportunities  for  devel- 


178  INTERMEDIATE   CUTTINGS  —  THINNINGS 

opment.  The  trees  capable  of  furnishing  the  largest  propor- 
tion of  clear  lumber  in  the  final  cut  will  be  found  in  the 
intermediate  crown  class.  They  have  long  clear  boles  which 
have  been  thoroughly  pruned  while  still  slender  and  all  subse- 
quent growth  will  be  clear  limiber.  Borggreve  in  his  succes- 
sive thinnings,  removing  the  relatively  poorly  formed  domi- 
nant trees,  advances  the  intermediate  trees  to  the  co-dominant 
and  finally  to  the  dominant  crown  class :  —  from  a  position 
where  only  a  small  amount  of  overhead  light  was  available 
to  a  commanding  place  in  the  stand  with  opportunity  for 
rapid  growth.  In  theory  trees  found  in  the  overtopped  class 
at  the  time  of  the  first  thinning  might  eventually  be  advanced 
to  the  dominant  class.     (See  Figs.  71,  72  and  73.) 

The  success  of  Borggreve's  method  hinges  upon  whether 
trees  which  have  been  crowded  and  overtopped  in  the  struggle 
for  existence  can  recover  and  become  thrifty  fast  growing 
individuals.  Undoubtedly  the  degree  to  which  the  process 
of  suppression  has  advanced  is  the  determining  factor  in  such 
recovery.  The  extent  to  which  overtopped  and  intermediate 
trees  can  be  expected  to  develop  into  first  class  dominant  trees 
will  vary  with  the  silvical  habits  of  the  species  and  the  site 
and  must  be  determined  in  each  case.  With  shade  enduring 
species  and  on  the  better  class  of  sites  there  is  more  oppor- 
tunity for  the  use  of  Borggreve's  principle  than  with  Ught 
demanding  species,  which  suffer  more  severely  from  suppres- 
sion, and  on  poor  sites  when  recovery  and  rate  of  growth 
after  thinning  is  slow. 

At  first  thought  it  might  seem  that  a  series  of  selection 
thinnings,  if  continued  long  enough,  must  eventually  produce 
an  unevenaged  stand  and  thus  be  properly  classed  as  repro- 
duction cuttings  under  the  selection  method,  rather  than  as 
intermediate  cuttings.  This  is  not  the  case.  The  selection 
thinnings  are  continued  only  until  the  reproduction  period  is 


s  ^ 


m  03 
2  .S 


to   o 


.y  o 
.s  ^ 


179 


^■5 


i8o 


•^ 

•-H 

"v! 

T3 

u 

^ 

^ 

!^ 

^ 

-0 

s 

Q 

i 

j2 

3 
o 

3 
O 

& 

^ 

rt 

o 

U 
O 

5 

1 

^ 

.2 

^ 

&: 

i 

Oj 

n 

m 

rt 

o 

^ 

fi 

hn 

JJ 

S 

-O 

_g 

•r) 
c 

£   £ 


N    2:^    ° 


!=!    S 


^, 

a 

-^ 

c 

E 

a 

nS 

.s 

i 

^ 

XI 

j:^ 

-n 

ti 

^ 

UJ 

Vi 

j:3 

T5 

H 

"^ 

rrf 

rt 

n 

.>i 

> 

^ 

.3 

S 

i8i 


l82  INTERMEDIATE   CUTTINGS  —  THINNINGS 

reached  and  are  strictly  intermediate  cuttings  intended  pri- 
marily for  application  in  evenaged  stands.  The  overtopped 
stand  serves  as  a  protective  cover  which  among  other  pur- 
poses has  the  effect  of  preventing  the  estabhshment  of  re- 
production under  any  large  openings  created  in  the  upper 
canopy. 

It  is  estimated  that  from  lo  to  40  per  cent  of  the  volume  in 
board  feet  of  the  stand  can  be  removed  in  a  selection  thinning. 
The  tendency  should  be  to  cut  Hghtly  rather  than  heavily.  A 
high  percentage  of  the  volume  in  board  feet  should  never  be 
removed  except  in  stands  where  only  a  few  of  the  larger 
trees  have  reached  sawable  size.  In  such  a  stand  a  light 
cutting  might  properly  remove  a  considerable  part  of  the 
board  feet  volume. 

Borggreve's  method  has  distinct  advantages  and  disad- 
vantages as  contrasted  with  the  other  two  methods. 

The  advantages  are: 

1.  The  thinning  returns  a  greater  profit  because  the  trees 
cut  in  the  main  stand  are  the  largest  and  ordinarily  at  that 
moment  the  most  salable  trees  in  the  stand.  Lumber  may 
be  the  chief  product  as  compared  with  cordwood  under  other 
methods. 

2.  A  better  quality  of  timber  is  produced,  because  only 
clean  boled,  small  limbed  trees  are  allowed  to  remain  until 
the  end  of  the  rotation. 

Among  the  disadvantages  may  be  mentioned: 
I.  The  rotation  must  be  lengthened  to  secure  tunber  of  a 
given  size.  Since  the  larger  individuals  are  removed  in  the 
thinnings  and  trees  at  one  time  in  the  lower  crown  classes  are 
developed  into  the  trees  for  the  final  harvest,  it  is  evident  that 
a  longer  time  will  be  needed  to  produce  given  dimensions. 
The  average  rate  of  growth  of  the  final  harvest  trees  will  be 
slower  than  under  either  the  ordinary  or  French  method.     An 


METHODS   OF  MAKING  THINNINGS  1 83 

increase  of  40  to  60  per  cent  in  the  length  of  the  rotation 
should  be  expected. 

2.  Reduction  of  the  growth  of  the  stand.  The  removal  of 
the  thriftiest  dominant  trees  leaves  large  openings  which  are 
supposedly  filled  by  rapid  expansion  of  trees  of  inferior  crown 
classes  which  remain.  Only  where  the  species  are  extremely 
shade  enduring,  the  site  good  and  the  thinnings  kept  light 
will  this  assumption  hold  good.  In  the  average  stand  re- 
peated use  of  Borggreve's  method  will  reduce  the  growth  and 
eventually  leave  a  body  of  trees,  formerly  in  overtopped  and 
intermediate  crown  classes,  which  are  suffering  from  exposure 
to  sun,  wind  and  insects  and  fail  to  conserve  the  factors  of 
the  site. 

3.  There  is  even  more  difficulty  experienced  than  in  the 
French  method  in  felling  the  large  trees  and  getting  the  mate- 
rial from  the  area  without  injury  to  or  hinderance  from  the 
subordinate  stand. 

Selection  thinnings  should  not  be  started  until  good  height 
growth  has  been  attained  and  natural  pruning  is  far  advanced. 
The  best  results  from  such  cuttings  will  be  obtained  when 
they  are  not  initiated  until  between  the  fiftieth  and  eightieth 
years  and  are  used  with  rotations  of  125  to  200  years  for  the 
production  of  high  quality  timber.  Before  the  Borggreve 
cuttings  are  begun,  light  thinnings  as  needed  under  the  ordi- 
nary method  may  be  employed.  The  disadvantages  are 
largely  overcome  if  a  late  initiation  of  the  method  is  combined 
with  early  thinnings  from  below  and  the  employment  of  a 
long  rotation. 

Special  Methods  of  Thinning.  —  Occasionally  stands  in 
great  need  of  a  thinning  are  found  of  such  density  as  to  make 
the  removal  of  individual  trees  in  a  thinning  operation  very 
difficult  and  expensive.  To  overcome  this  special  methods 
can  be  employed.     Young  stands,  10  to  20  years  old,  of  un- 


i84 


INTERMEDIATE   CUTTINGS  —  THINNINGS 


merchantable  trees  so  dense  as  to  be  in  danger  of  stagnation 
of  growth  unless  thinned,  furnish  an  illustration. ^^  The  indi- 
vidual trees  may  stand  so  closely  together  that  it  is  a  laborious 
task  to  reach  and  cut  each  individual  that  should  be  removed 
in  the  thinning.  Instead  of  attempting  this  narrow  lanes 
three  to  four  feet  in  width  may  be  clear  cut,  running  through 
the  stand  at  intervals  of  5  to  10  feet.  The  cutting  can  be 
done  in  the  lanes  easily  and  quickly.     (See  Fig.  74.) 

In  dense  stands  of  merchantable  size  there  is  space  enough 
to  cut  through  the  trunk  with  the  axe  or  saw,  but  the  severed 


Fig.  74- 
A  thinning  in  an  unmerchantable  stand  15  years  of  age  an'd  so  dense  as  to 
require  immediate  treatment.  Narrow  lanes  were  cut  through  the  stand  and 
the  trees  felled  into  and  left  lying  in  these  lanes.  Not  an  ideal  method  of  thin- 
ning, but  done  to  reduce  the  cost  to  a  reasonable  amount.  Windrows  of  feUed 
trees  are  indicated  by  crosshatching. 

tree  remains  standing  upright  and  it  is  difficult  to  bring  it  to 
the  ground.  Such  a  condition  occurs  only  with  shade  en- 
during species  Hke  red  spruce  (Picea  rubens)  having  stiff 
branches,  which  often  persist  on  the  trees  for  years  after 
death.  In  a  dense  stand  of  red  spruce,  30  to  60  years  of  age, 
it  may  be  impossible  to  bring  a  severed  tree  to  the  ground 
except  by  dragging  the  butt  away  from  the  stump  (usually 
with  the  aid  of  horses),  until  the  top  is  pulled  loose  from  the 
surrounding  crowns.  This  is  too  expensive  an  operation. 
Cutting  clear  of  lanes  wider  than  those  in  young  unmerchant- 
able stands  is  ad  vised. ^^  The  lanes  may  be  8  to  10  feet  wide 
with  uncut  strips  10  to  18  feet  in  between.     The  difficulty  of 


APPLICATION  OF  THINNINGS 


^85 


bringing  the  trees  to  the  ground  is  overcome  and  the  logging 
is  cheapened  because  the  felled  material  is  concentrated  in 
the  lanes. 

When  the  same  stand  is  thinned  a  second  time  the  lanes 
can  be  run  at  right  angles  to  those  cut  in  the  first  operation. 
In  principle  a  thinning  of  tliis  character  is  not  fully  satis- 


fi    h 

^"^ 

^ 

^ 

K 

\\NN 

V$^ 

'W 

$^ 

iV 

$w\ 

bjo        \ 

V  \  \  \  ^ 

\  \j 

6J0    \  \ 

^       I 

\\\  \ 

.S    '  W 

\  \  I 

a      l\^ 

.  \  \  \ 

N'    -s    K 

\\\N 

\\i 

■3    V\ 

\  \  \ 

1     ^     K 

\  \  \  \ 

a     |\  ^ 

^  2   K 

\\\\ 

^     '\\\ 

\  \  1 
\  \ 

^    k\ 

\  \  \ 

'      ^       K 

\  \\  \ 

^  Av 

\\ 

H       [\^ 

\  \  \  \ 

^  ^   N 

\  \  \ 

-s  rA> 

\\{ 

^   K\ 

\  \\ 

\l     ^      K 

■*-"            IV      \      \ 

\  \ 

-^     \ 

v^   .a    i\ 

\    \    \    \ 

.a   \v 

\\  1 

fl    k\ 

\  \  \  \ 

J  ^  ^ 

\\\\ 

^   k\\ 

\\ 

'Z    C\ 

\  \  \ 

n     "^      \ 

c3          \    \   ^ 

^  \  1 

=*      \  \ 

(-2    1 

\\\\ 

«i        k\  \ 

\\ 

OJ         l\ 

\  \  \ 

sj     0    K 

\     \     \     \ 
\     \     \ 

0    NAA 

\  \^ 

"    k\ 

\  \  \ 

■^    1  ^ 

\  \  \  \ 

\  \  1 

-^      \ 

\  \  \  ^ 

\     ^    k 

\  \  \  \ 

s    k\\ 

\  \ 

s      k  \ 

1    ^    i\ 

AW 

0    i\\\ 

\  \  1 

Q    K^ 

\  \  \  \ 

1       K 

[\v 

\^ 

tv 

\\\ 

h     K 

\\\ 

^ 

I  \ 

\\v 

Fig.  75. 

Portion  of  a  dense  stand  of  60  year  old  timber  treated  with  a  strip  thinning 
Strips  10  feet  in  width  have  been  cut  leaving  uncut  strips  18  feet  wide.  The 
trees  on  the  edges  of  these  strips  have  opportunity  for  increased  growth. 

factory  but  does  furnish  opportunity  for  the  trees  on  the  sides 
of  the  clear  cut  lanes  to  increase  their  rate  of  growth.  (See 
Figs.  75  and  76.) 

Application  of  Thinnings.  —  It  has  already  been  indicated 
that  thinnings  should  be  started  as  early  in  the  life  of  the 
stand  as  the  need  arises,  but  that  in  practice  they  are  Hkely 
to  be  deferred  on  account  of  the  cost  until  the  time  when  the 
material  removed  can  pay  for  the  operation.     This  is  a  good 


i86 


INTERMEDIATE   CUTTINGS  —  THINNINGS 


rule  to  be  broken  only  in  special  cases,  where  the  owner  is 
willing  to  invest  the  cost  of  the  thinning  and  where  the  ultimate 
financial  benefits  of  the  operation  are  clearly  discernible. 

As  soon  as  the  openings  made  by  the  preceding  thinning 
have  closed  a  second  cutting  should  be  made.  The  interval 
between  cuttings  may  vary  from  3    to   10  years,  or  even 


^ 


t>c      i\\\\\       M        \\^ 

.S   t.  .3  a 

-     ""         Cut  clear     h         in  Second       ^      Thinning 


Cut  clear 


in  Second 


Thinning 


Fig 


Same  stand  as  in  Fig.  75,  but  10  years  later  after  a  second  strip  thinning  has 
been  made.  The  strips  in  this  case  were  cut  at  right  angles  to  the  first  strips. 
The  timber  left  (shown  by  cross-hatching)  is  in  the  form  of  compact  groups. 
The  trees  on  the  edges  have  opportunty  for  increased  growth,  but  the  trees 
standing  in  the  center  of  the  groups  have  not  been  benefited. 

longer  in  exceptional  cases,  depending  primarily  upon  the 
severity  of  the  thinning,  the  quality  of  the  site  and  the  in- 
herent ability  of  the  species  to  take  advantage  of  the  in- 
creased opportunity  for  growth.     (See  Figs.  68  and  77.) 

On  a  good  site  thinnings  can  be  repeated  frequently,  and 
each  thinning  may  be  relatively  heavy  because  of  the  rapidity 


APPLICATION  OF  THINNINGS       '  187 

of  growth  on  good  soils.  As  the  stand  grows  older  the  inter- 
val between  thinnings  is  apt  to  lengthen,  because  growth  may 
slow  up  and  the  openings  in  the  canopy  average  larger  due  to 
the  larger  crown  spread  of  single  older  trees. 


Fig.  77. 

The  same  stand  as  shown  in  Fig.  68,  but  10  years  after  the  D  grade  thinning 
was  made.  The  crown  canopy  is  almost  complete.  The  stand  is  in  need  of  a 
second  thinning. 

Thinnings  should  be  carried  on  systematically  from  early 
in  the  hfe  of  the  stand  until  the  period  of  regeneration,  fol- 
lowing a  definite  policy.  What  method  of  thinning  should 
be  used  and  how  severe  the  thinnings  ought  to  be  made,  must 
be  determined  separately  for  each  case.  All  that  can  be 
attempted  here  is  to  indicate  the  procedure  in  some  of  the 
commoner  cases. 


l88  INTERMEDIATE   CUTTINGS— THINNINGS 

Where  a  large  percentage  of  clear  lumber  is  desired  the 
stand  must  be  kept  fairly  dense,  and  moderate  thinnings 
will  be  in  order.  If  large  volume  production  is  wanted  with- 
out a  product  of  high  technical  quality,  then  thinnings  at 
least  as  heavy  as  Grade  C  under  the  ordinary  system  prove 
the  best.  WTiere  lumber  of  wide  dimension  is  demanded, 
even  if  somewhat  knotty,  very  heavy  thinnings  can  be  made. 

Shade  enduring  trees  can  grow  thriftily  with  less  Hght  than 
the  light  demanding  species  and  do  not  receive  such  heavy 
thinnings  as  the  latter. 

The  German  and  French  methods  will  be  used  oftener  than 
Borggreve's.  One  thinning  under  the  latter  method  and  then 
reversion  to  one  of  the  other  methods  may  meet  the  situation 
in  many  somewhat  irregular  stands,  previously  unthinned, 
and  in  localities  where  to-day  only  the  bigger  trees  afe  saleable. 
Between  the  German  and  the  French  methods  the  choice. is 
difl&cult  and  may  be  decided  by  existing  market  conditions  in 
favor  of  the  French  idea. 

The  ordinary  method  in  its  lower  grades  A  and  B  does 
little  more  than  utilize  trees  which  would  otherwise  be  wasted. 
The  growth  of  the  stand  cannot  be  stimulated  by  removing 
only  those  trees  which  already  are  conquered  in  the  struggle 
for  existence.  Grades  C  and  D  are  needed  to  secure  this 
result,  and  are  the  grades  advised  in  most  cases  when  the 
ordinary  method  is  employed. 

Use  of  all  three  methods  combined  in  the  same  stand  to  fit 
variation  in  conditions  encountered  is  often  the  wisest  course. 

Thinnings  can  well  be  increased  in  severity  with  advancing 
age  in  order  to  satisfy  the  demands  of  the  trees  for  more  Kght 
and  room.  Indeed,  due  to  the  larger  crown  spread  of  the 
individual  trees  in  an  older  stand,  bigger  gaps  must  be  left 
if  any  thinning  is  made. 

In  applpng   thinnings   the  danger   from  windthrow  and 


REFERENCES  189 

breakage  must  be  kept  in  mind.  If  the  work  is  started  early 
any  stand  can  be  made  comparatively  resistant  to  storms  by 
systematic  thinning.  The  development  must  be  gradual.  If 
thinned  too  heavily  at  first  the  entire  remaining  stand  may 
be  lost.  Dense  stands  of  tall,  small  crowned  trees  which  have 
gone  for  years  unthinned  reach  a  stage  when  it  is  dangerous 
to  make  even  a  Hght  thinning.  Timber  of  this  character 
ordinarily  must  be  left  untouched  until  ready  for  regenera- 
tion. Danger  of  windfall  after  thinnings  is  greatest  on  wet 
ground,  thin  soil  and  exposed  sites  and  with  shallow  rooted 
species. 

Plantations  closely  spaced  (6x6  feet  or  less)  will  require 
thinning  soon  after  they  close.  So  many  individuals  in  a 
plantation  are  all  of  about  the  same  size  and  vigor  when  they 
meet  that  an  even  but  severe  struggle  takes  place,  which  is 
apt  to  leave  all  the  contestants  aHve  and  seriously  weakened. 
If  thinnings  are  impracticable,  this  should  be  allowed  for  by 
using  wide  spacing  in  the  plantation. 


REFERENCES 

1.  KuNZE,  Max.  Untersuchungen  iiber  den  Einfluss  verschiedener 
Durchforstungsgrade  auf  den  Wachstumsgang  eines  Kiefernbestandes.  Mit- 
teilungen  aus  der  Konig.  Sachsischen  forstlichen  Versuchsanstalt  zu  Tharandt. 
Band  i,  Heft  2,  1913. 

2.  Caccia,  a.  M.  Forest  Research  at  Cambridge.  Quarterly  Journal  of 
Forestry,  Vol.  VIII,  1914,  p.  130. 

3.  Biennial  Report  of  the  Forestry  Commission,  State  of  New  Hampshire, 
for  the  years  1905-1906,  pp.  238  and  249. 

4.  Cook,  H.  O.  Forest  Mensuration  of  the  White  Pine  in  Massachusetts, 
State  Forester's  Office,  Boston,  1908,  pp.  21  and  30. 

5.  ScHLiCH,  W.  Manual  of  Forestry.  3rd  edition.  London,  1905.  Pp. 
345-347,  350-351,  362-363  and  366-367. 

6.  Wood,  B.  R.  Increment  Fellings  with  Some  Possible  Applications  to 
the  Chir  Pine.     Indian  Forester,  Vol.  42,  1916,  pp.  283-286. 

7.  NiSBET,  J.     Studies  in  Forestry.     O.xford,  1894.     P.  196. 


igo  INTERMEDIATE   CUTTINGS  —  THINNINGS 

8.  Graves,  H.  S.     Principles  of  Handling  Woodlands.     Wiley  &  Sons, 
Inc.,  New  York,  1911.     Pp.  210-211. 

9.  Fernow,  B.  E.     a  Forest  Policy  for  Massachusetts.      Forestry  Quar- 
terly, Vol.  2,  1904,  p.  66. 

10.  BORGGREVE,  BERNARD.     Die  Holzzucht.     2nd  edition.     Berlin,  1891. 

11.  Sterrett,  W.  D.     Jack  Pine.     Bulletin  820,  United  States  Depart- 
ment of  Agriculture,  Washington,  1920,  p.  s3- 

12.  Hawley,  R.  C.,  and  Hawes,  A.  F.     Forestry  in  New  England.    Wiley 
&  Sons,  Inc.,  New  York,  1912.     Pp.  226-228. 

Ashe,  W.  W.  Shortleaf  Pine  in  Virginia.  The  Increase  in  Its  Yield  by  Thin- 
ning. Department  of  Agriculture  and  Immigration  of  Virginia,  Richmond, 
1913- 

BoRGMAN.    Forstliche  Tagesfragen.    Tharandter  ForstUches  Jahrbuch,  Vol.  65, 

1914,  pp.  351-376. 

BoRGMAN.    ForstHche  Tagesfragen.     Tharandter  ForstUches  Jahrbuch,  Vol.  66, 

1915,  pp.  60-93. 

Frothingham,  E.  H.  Second-Growth  Hardwoods  in  Connecticut.  Bulletin 
96,  Forest  Service,  United  States  Department  of  Agriculture,  Washington, 
1912,  pp.  49-54. 

Hawes,  A.  F.  Economic  Thinning  of  White  Pine.  Forestry  Quarterly,  Vol. 
5,  1907,  pp.  368-372. 

Heck,  C.  R.     Freie  Durchforstung.     Berlin,  1904. 

Hemman.  Ueber  die  Abhangigheit  der  Ertragsregelung  und  Bestandsplege 
vom  Versuchs-wesen.  AUgemeine  Forst-  und  Jagdzeitung,  1915,  pp.  112- 
116. 

Hemman.  Durchforstungs-  und  Lichtimgstafeln  nach  den  Normalertagstafehi 
der  deutschen  Versuchsanstalten.     Berlin,  1913. 

Hubbard,  W.  F.  Forest  Thinning  and  Its  Results.  Reprint  from  Forestry 
and  Irrigation  for  June  and  July,  1904,  Washington,  1904. 

Laschke,  C.     O  Konomik  Durchforstungsbetreibes.     Neudamm,  1901. 

Laschke,  C.  GeschichtUche  Entwickelung  des  Durchforstungsbetreibes  im 
Wissenschaft  und  Praxis,  Neudamm,  1902. 

Mattoon,  W.  R.  Shortleaf  Pine:  Its  Economic  Importance  and  Forest  Man- 
agement. Bulletin  308,  United  States  Department  of  Agriculture,  Wash- 
ington, 1915,  pp.  34-35. 

Murphy,  L.  S.  The  Red  Spruce:  Its  Growth  and  Management.  Bulletin 
544,  United  States  Department  of  Agriculture,  Washington,  191 7,  pp. 
53-59- 

Schubert.  Die  Hochdurchforstung  im  Laubwalde.  Forstwissenschafthches 
Centralblatt,  September-October,  1909,  pp.  461-474. 

Schwappach.  Bestandespflege  in  Buchenbestanden  der  Oberforsterei  Freien- 
walde.     Zeitschrift  fiir  Forst-  und  Jagdwesen,   Beriin,  191 2,  pp.  386-390. 


REFERENCES  191 

Sterrett,  W.  D.,  Forest  Management  of  Loblolly  Pine  in  Delaware,  Mary- 
land and  Virginia.  Bulletin  II,  United  States  Department  of  Agriculture, 
Washington,  1914,  pp.  38-40. 

ijber  Nachhaltige  Massenentnahmen  ohne  Flachenverrechnung.  Forstwissen- 
schaftliches  Centralblatt,  191 5,  pp.  23-26. 

Williamson,  A.  W.  Cottonwood  in  the  Mississippi  Valley.  Bulletin  24, 
United  States  Department  of  Agriculture,  Washington,  1913,  pp.  39-42. 

WiMMENAUER.  Durchforstungsvcrsuche  in  Buchen-  und  Kiefem-bestanden. 
AUgemeine  Forst-  und  Jagdzeitung,  March,  1914,  pp.  84-90. 

WooLSEY,  T.  S.,  Jr.  Strip  Thinnings.  Proceedings  of  the  Society  of  Amer- 
ican Foresters,  Vol.  6,  1911,  pp.  38-41. 


CHAPTER  XI 
INTERMEDIATE  CUTTINGS    (Continued) 

Improvement  Cuttings.  —  Cuttings  made  in  a  stand  past 
the  sapKng  stage  for  the  purpose  of  improving  the  composi- 
tion and  character  by  removing  trees  of  undesirable  species, 
form  and  condition. 

The  operation  resembles  both  a  cleaning  and  a  thinning  in 
character.  It  is  needed  only  in  stands  in  which  cleanings 
were  not  made  early  in  the  rotation.  Most  of  the  unmanaged 
stands  containing  more  than  one  species  are  in  need  of  such  a 
cutting. 

In  a  stand  of  this  kind  trees  of  undesirable  species  or  poor 
form  are  likely  to  be  in  dominant  position  overtopping  more 
valuable  individuals  and  many  intermediate  and  overtopped 
trees  overcome  in  the  struggle  for  existence  need  cutting. 
The  removal  of  dominant  trees  of  undesirable  species  and 
poor  form  is  like  unto  a  cleaning,  while  the  cutting  of  the 
trees  of  lower  crown  classes  in  a  measure  resembles  a  thinning. 
(See  Fig.  78.) 

In  the  selection  of  the  trees  to  be  taken  out  in  the  combined 
operations  the  principles  laid  down  for  the  making  of  cleanings 
and  thinnings  should  be  followed. 

One  improvement  cutting  may  be  sufficient  to  regulate  the 
mixture  in  the  stand  and  if  so  then  subsequent  cuttings  will 
be  in  the  nature  of  thinnings.  There  may  be  so  many  trees  of 
undesirable  species  or  poor  form  in  the  dominant  stand  that 
their  removal  all  at  one  time  would  result  in  too  severe  open- 
ing up  of  the  canopy.  A  second  and  even  a  third  improve- 
192 


194  INTERMEDIATE   CUTTINGS 

merit  cutting  may  have  to  be  made  before  the  mixture  is 
satisfactory. 

In  stands  managed  from  early  youth  cleanings  made  at  the 
proper  time  will  eliminate  the  necessity  for  improvement  cut- 
tings at  a  later  date.  Where  economic  conditions  prohibit 
early  cleanings  there  will  be  opportunity  for  the  use  of  im- 
provement cuttings.  In  contrast  with  cleanings  improvement 
cuttings  yield  material  always  large  enough  for  cordwood  and 
hence  may  yield  a  profit.  Like  thinnings  they  should  be  made 
only  when  the  products  secured  will  pay  the  expense  of  the 
operation. 

It  is  much  better  from  the  silvicultural  standpoint  that 
cleanings  rather  than  improvement  cuttings  be  employed. 
Where  undesirable  species  are  allowed  to  occupy,  until  of 
salable  size,  a  dominant  position  for  a  series  of  years,  during 
which  severe  competition  between  individuals  is  in  progress, 
the  growth  of  the  overtopped  but  more  valuable  species  will 
be  checked  and  their  development  seriously  curtailed 

Salvage  Cuttings.  —  Cuttings  made  for  the  purpose  of  re- 
moving trees  killed  or  damaged  by  various  injurious  agencies 
are  termed  salvage  cuttings.  "  Damage  cutting  "  is  a  synony- 
mous term.     (See  Fig.  79.) 

Damage  in  the  forest  due  to  fungi,  insects,  fire,  wind,  snow 
and  other  agencies  is  occurring  continuously  and  frequently 
reaches  serious  proportions  in  a  given  stand.  The  removal  of 
trees  injured  by  their  neighbors  in  the  struggle  for  existence 
does  not  constitute  a  salvage  cutting,  but  falls  under 
thinnings. 

Salvage  cuttings,  as  the  name  indicates,  attempt  to  utilize 
the  injured  trees  with  the  idea  of  minimizing  the  loss.  There 
is  no  skill  required  in  selecting  the  trees  to  be  taken  out  other 
than  abiHty  to  recognize  those  that  have  injuries  necessitating 
removal. 


SALVAGE   CUTTINGS 


195 


The  severity  of  the  cutting  depends  entirely  upon  the  pro- 
portion of  the  stand  occupied  by  the  damaged  trees.  On  this 
basis'  a  salvage  cutting  may  range  in  character  from  a  thin- 
ning to  a  clearcutting. 

Salvage  cuttings  are  not  made  unless  the  material  taken 
out  will  at  least  pay  the  expense  of  the  operation.     Excep- 

A  =  Fire  scars.      B  =  Stagheaded  tree.      C  =  Canker.      D  =  Killed  by  insects. 


Fig.  79. 

A  stand  in  need  of  a  salvage  cutting.  The  injured  trees  are  indicated  by- 
dashes.  So  many  trees  require  cutting  that  the  remaining  stand  will  be  irregu- 
lar and  open.     Reproduction  will  be  needed  to  fill  the  openings. 

tions  to  this  statement  occur  when  it  becomes  essential  for  the 
safety  of  the  surrounding  forest  to  remove  unmerchantable 
trees  attacked  by  insects  or  fungi. 

Even  though  the  damaged  material  can  be  salvaged  at  a 
profit  the  injuries  which  made  the  operation  necessary  ordi- 
narily occasion  an  ultimate  loss.  This  is  true  especially  when 
stands  in  the  first  half  of  the  rotation  are  damaged.  The 
loss  is  due  partly  to  deterioration  of  the  injured  trees  before 
being  salvaged,  partly  to  a  reduction  in  the  density  of  stocking, 
with  the  possibihty  that  a  portion  of  the  area  may  be  unpro- 
ductive, and  partly  to  the  tutting  of  the  injured  trees  before 
they  had  attained  the  size  and  could  furnish  the  products 
desired  by  the  owner. 


196  INTERMEDIATE  CUTTINGS 

Wherever  extensive  injury  has  occurred,  and  provided  the 
condition  of  the  stand  permits,  reproduction  cuttings  should 
be  initiated  and  a  new  stand  estabhshed.  It  is  better  to 
remove  the  remaining  healthy  trees  along  with  the  damaged 
ones  rather  than  leave  the  former  in  too  open  a  stand. 

Nearly  all  heavy  salvage  cuttings  are  followed  by  reproduc- 
tion of  some  sort  or  by  a  growth  of  grass,  weeds  or  brush. 
Where  fire  was  the  source  of  the  damage  the  subsequent  re- 
production is  apt  to  be  of  undesirable  species. 

Artificial  regeneration  is  often  needed  after  a  salvage  cutting. 

While  fire,  fungi,  insects,  wind,  etc.,  may  be  looked  upon 
as  accidental  factors,  yet  injuries  from  these  causes  are  of 
such  common  occurrence  as  to  make  salvage  cuttings  an 
expected  and  frequently  used  operation. 

Severance  Cuttings.  —  Cuttings  made  by  clearing  a  nar- 
row strip  along  the  edge  of  a  young  stand  for  the  purpose  of 
developing  a  belt  of  windfirm  trees  along  the  border  of  the 
stand.     (See  Figs.  80  and  81.) 

In  a  forest  under  management,  consisting  of  evenaged 
stands  of  many  different  ages,  the  cutting  of  one  stand  may 
expose  another  adjacent  stand,  where  it  abutts  closely  to  the 
one  harvested,  to  injury  by  wind  and  to  a  lesser  extent  along 
the  border  to  sunscald. 

To  avoid  such  injuries  the  creation  of  narrow  cleared  lanes 
between  adjacent  stands  by  severance  cuttings  is  advisable. 
The  effect  of  the  cutting  is  to  stimulate  crown  and  root  de- 
velopment of  the  trees  bordering  the  lane.  They  become 
more  windfirm  and  through  the  maintenance  of  a  Hving 
crown  low  down  on  the  stems  on  the  border  of  the  lane  pro- 
tect the  boles  from  sunscald  and  prevent  the  free  entrance 
of  strong  winds  into  the  interior  of  the  stand.  The  high  un- 
derbrush likely  to  spring  up  at  the  edges  of  the  lane  increases 
the  protection. 


Scale:-!  Inch  =  800  Feet 
Fig.  8o. 
Diagram  of  a  small  forest  property  divided  into  six  stands  separated  from  one 
another  by  severance  cuttings. 


Severance/VVV'VVVV^VA 
Cutting/  15  Year  Old  Stand 

Qf~rri"rT'n"i"", 


Fig.  8i. 
Severance  cutting  between  an  80  year  and  a  15  year  old  stand.     Note  the 
dense  growth  of  shrubs  and  overtopped  trees  which,  together  with  the  tree 
crowns,  forms  a  wind  mantle  along  the  side  of  the  stand. 

197 


1 98  INTERMEDIATE   CUTTINGS 

Severance  cuttings  should  be  made  early  in  the  rotation 
before  natural  pruning  has  progressed  far,  as  the  development 
of  windfirm  individuals  is  a  gradual  process. 

Until  a  forest  is  organized  for  continuous  production  and 
definitely  divided  into  stands  severance  cuttings  will  find 
slight  application.  Fire  lines  developed  in  the  effort  to  pre- 
vent and  control  forest  fires  will  in  many  tracts  serve  as 
severance  cuttings,  although  not  recognized  as  such  at  the 
present  time. 

Pruning.  —  This  operation  removes  branches  from  stand- 
ing trees  for  the  purpose  of  increasing  the  quahty  of  the  final 
product. 

For  the  production  of  clear  lumber  the  death  and  early 
removal  of  all  limbs  from  the  main  stems  of  trees  are  essential. 
This  may  be  accomphshed  in  the  forest  naturally  by  means 
of  the  crowding  and  shading  of  the  individual  trees.  In  fact 
good  natural  pruning  is  the  chief  advantage  of  the  dense 
stands.  Under  certain  conditions  Nature's  process  is  fully 
satisfactory  and  produces  a  high  percentage  of  clear  lumber. 
It  requires  great  density  of  stand,  with  correspondingly  slow 
growth  of  the  individuals  and  a  comparatively  long  rotation 
to  accomphsh  nature's  results. 

Nothing  better  can  be  expected  where  silvicultural  prac- 
tice must  be  of  a  crude  and  extensive  nature.  When  inten- 
sive methods  are  possible,  applied  silviculture  aims  to  reduce 
the  density  of  the  stand  found  in  nature,  with  the  purpose  of 
obtaining  a  reduction  in  the  length  of  time  necessary  to 
produce  lumber  of  a  given  size.  (See  chapter  on  Thinnings.) 
The  long  rotations,  which,  in  the  virgin  forest,  have  accumu- 
lated stores  of  clear  lumber  developed  under  Nature's  method 
of  pruning,  cannot  be  tolerated  in  the  managed  forest  due  to 
their  poor  financial  showing.  In  order  to  produce  a  reason- 
able percentage  of  clear  lumber  on  a  short  rotation  in  stands 


PRUNING  199 

kept  growing  at  their  fastest  rate,  artificial  pruning  often  will 
be  required.  In  plantations  the  argument  has  especial  weight. 
Here  in  order  to  save  expense  trees  are  set  out  at  the  rate  of 
800  to  2500  per  acre,  with  the  average  number  around  1000 
to  1200.  As  compared  with  the  stands  of  several  thousand 
trees  per  acre  frequently  starting  on  areas  naturally  repro- 
duced, this  is  a  small  number  and  results  in  a  stand  not  very 
densely  stocked.  Such  plantations,  if  they  are  to  yield  clear 
lumber  in  appreciable  amount,  demand  artificial  pruning. 

The  inherent  ability  of  the  species  to  prune  naturally  is  of 
fundamental  importance  in  determining  the  need  of  artificial 
pruning.  Light  demanding  species  on  the  whole  prune  more 
quickly  and  completely  than  shade  endurers;  but  this  is  not 
an  infalUble  rule.  Certain  species,  of  which  red  oak  {Quercus 
rubra)  is  one,  prune  naturally  much  better  than  other  species 
which  are  more  light  demanding. 

Forest  pruning  may  consist  in  the  removal  of  either  dead 
limbs  or  Hve  limbs.  It  is  evident  that  there  can  be  no  harm 
to  the  tree  through  pruning  dead  limbs.  The  removal  of 
live  Umbs  may  be  the  source  of  injury  in  two  ways: 

(a)  Fungi  and  insects  are  afforded  opportunity  to  enter  the 
tree  through  the  branch  scars.  Where  only  small  branches 
are  cut  the  wounds  may  heal  over  quickly  and  injury  be 
prevented. 

{b)  The  balance  existing  between  the  crown  and  the  root 
systems  is  disturbed  and  as  a  consequence  the  growth  is 
Hkely  to  be  retarded.  The  extent  to  which  this  may  occur 
depends  upon  the  proportion  of  the  Hve  crown  which  is 
removed  in  the  pruning. 

As  an  example  of  the  effect  of  live  pruning  on  height  growth 
the  following  figures  relating  to  an  experiment  conducted  by 
the  author  in  a  white  pine  {Piniis  Strobus)  plantation  are 


200 


INTERMEDIATE   CUTTINGS 


given.     The  pruning  was  done  between  the  1916  and  191 7 
growing  seasons. 


Figures  of  Height  Growth  to  Show  Effects  of  Pruning 


Treatment 

Number 
of  trees 

Annual  height  growth  in  feet  for  the  year 

191S 

1916 

1917 

1918 

Pruned 

112 
169 

1.87 
I -53 

2.13 
1-75 

1-45 
1-95 

1-43 
2.13 

The  pruning  was  done  in  a  plantation  spaced  6x6  feet 
after  its  eighth  growing  season.  The  main  stand  ranged 
from  6  to  12  feet  in  height  and  had  not  completely  closed. 
The  branches  clear  to  the  base  of  the  trees  were  still  alive. 
All  but  the  last  three  and  in  a  few  cases  the  last  two  whorls 
of  live  branches  were  removed,  reducing  the  crown  by  about 
50  per  cent.  As  a  result  of  this  very  severe  pruning  the 
height  growth  of  the  pruned  trees  decreased  approximately 
one- third. 

Pruning  of  live  limbs  to  a  limited  extent  (for  not  over 
ID  per  cent  of  the  depth  of  the  live  crowns)  is  not  likely  to  have 
injurious  effects,  if  done  in  young  stands  when  the  branches 
are  small. 

Pruning  should  not  be  extended  to  all  the  trees  in  the 
stand,  but  only  to  the  relatively  small  number  of  the  best 
dominant  trees  which  will  form  the  final  crop.  It  is  an 
unprofitable  investment  to  prune  trees  which  will  die  a  nat- 
ural death  or  be  removed  before  the  end  of  the  rotation. 
The  number  selected  for  pruning  is  Hkely  to  fall  between  100 
and  200  trees  per  acre. 

Pruning  becomes  more  expensive  as  it  is  carried  higher  up 
the  tree,  because  the  trees  either  have  to  be  climbed  or  the 


PRUNING  20I 

pruning  carried  on  with  tools  mounted  on  long  poles.  In 
practice  it  is  customary  to  prune  high  enough  to  produce  clear 
lumber  for  the  first  i6  to  25  feet  above  the  ground.  A  large 
proportion  of  the  tree's  volume  will  be  contained  in  the  butt  log. 
If  the  financial  returns  made  possible  by  pruning  are  large, 
then  it  may  pay  to  prune  an  additional  log  or  two,  but  for 
the  present  the  securing  of  a  clear  butt  log  is  as  far  as  the 
operation  is  likely  to  be  extended. 

Pruning  should  be  started  early  because  the  limbs  to  be 
cut  will  then  be  smaller  and  the  core  of  knotty  wood  already 
produced  will  be  of  small  diameter.  There  is  Httle  use  in 
starting  in  the  last  half  of  the  rotation  to  prune  trees  which 
are  already  of  merchantable  size  and  whose  limbs  are  large 
and  expensive  to  cut.  The  belt  of  clear  wood  added  on  such 
trees  may  not  be  thick  enough  to  pay  for  the  operation. 
Instead  the  pruning  should  commence  when  the  lower  branches 
first  start  to  die  and  at  intervals  of  a  few  years  be  continued 
on  up  the  tree,  until  the  desired  length  is  freed  of  branches. 
This  applies  whether  dead  limbs  only  are  cut  or  dead  and 
some  live  branches  in  addition.  It  will  require  several  (three 
to  four)  prunings  to  clear  the  trunk  of  branches  for  16  to  25 
feet  above  the  ground,  but  as  one  hundred  or  more  trees  on  an 
acre  are  pruned  the  work  can  be  economically  conducted. 
Considering  the  saving  in  cutting  small  branches  instead  of 
large  ones,  the  cost  of  several  partial  prunings  as  contrasted 
to  one  complete  pruning  should  be  cheaper. 

Where  dead  limbs  only  are  pruned  the  work  may  be  per- 
formed during  any  convenient  season  of  the  year.  In  pruning 
five  limbs  it  is  best  to  conduct  the  operation  when  the  tree  is 
dormant.  This  is  the  period  recommended  for  pruning  in 
orchard  management  as  giving  the  best  results  in  subsequent 
wood  growth,  healing  of  the  wounds  and  freedom  from  infec- 
tion by  fungi. 


202  INTERMEDIATE   CUTTINGS 

Various  tools  may  be  used  in  forest  pruning.  For  general 
use  on  branches  of  all  sizes  and  particularly  on  work  at  a 
distance  from  the  ground  higher  than  a  man's  head,  the  small 
pruning  saws  commonly  used  in  horticultural  work  cannot 
be  excelled.  The  writer  prefers  a  curved  saw  with  teeth  on 
both  edges  and  with  the  teeth  on  one  edge  arranged  to  cut  on 
the  downward  pull.  Saws  leave  a  rough  surface  but  do  not 
injure  the  tree. 

A  sharp  axe  or  hatchet  is  an  excellent  tool  in  skilled  hands, 
but  when  carelessly  used  is  liable  to  wound  the  trunk  of  the 
tree  above  and  below  the  severed  branch.  Pruning  shears 
can  be  used  for  small  branches  less  than  one-half  to  one  inch 
in  diameter.  A  cutting  tool  leaves  a  smooth  surface.  In 
removing  branches  out  of  reach  from  the  ground  the  pruning 
tool  must  either  be  mounted  on  a  pole  or  else  a  ladder  used 
to  climb  with.  For  distances  up  to  i6  to  25  feet  the  long 
pole  is  more  economical  than  use  of  a  ladder.  A  chisel 
mounted  on  a  pole  is  an  effective  tool. 

With  any  tool  the  cuts  should  be  made  close  to  the  trunk, 
smooth  so  as  to  heal  over  quickly  before  fungi  or  insects  enter, 
and  without  tearing  or  loosening  the  bark  from  the  branch  stub. 

Pruning  requires  a  present  expenditure  for  the  purpose  of 
increasing  the  unit  value  of  the  final  product.  The  probable 
returns  to  be  expected  can  be  estimated  more  accurately  than 
in  some  other  lines  of  silvicultural  work,  so  that  it  should 
be  easy  in  any  case  to  decide  upon  the  advisability  of  the 
operation.  The  cost  of  pruning  is  apt  to  be  between  2  and 
10  cents  per  tree. 

An  example  of  a  rather  radical  system  of  pruning  is  that 
advocated  by  Knapp  ^  for  white  pine  {Pinus  strohus) .  His 
plan  involves  the  pruning  of  100  to  150  trees  per  acre  up  to  the 
height  of  17  feet.  The  pruning  is  started  before  the  lower 
branches  die,  or  become  over  one-half  inch  in  diameter,  and 


REFERENCES  203 

removes  two  or  three  whorls  of  branches  at  intervals  of 
three  to  four  years.  The  live  crown  is  maintained  at  one- 
half  to  one-third  the  total  height  of  the  tree.  At  the  age  of 
20  years  the  tree  is  26  feet  high,  4  inches  in  D.  B.  H.  with  a 
top  three  inches  outside  the  bark  at  17  feet  above  ground 
and  live  crown  eight  feet  in  diameter.  From  this  point  on 
all  branches  are  kept  alive  by  thinnings  and  a  diameter 
growth  maintained,  at  top  of  the  first  log,  of  0.4  or  0.5  inch 
per  year.  The  cost  of  this  pruning  amounts  to  10  cents  per 
tree  at  20  years  or  $4  to  $5  per  thousand  feet  board  measure 
at  end  of  a  50  year  rotation.  The  value  of  one-half  the  lum- 
ber is  raised  from  $20  to  $40  per  thousand,  which  indicates 
a  handsome  return  from  the  pruning. 

As  intensive  silviculture  develops,  pruning  is  an  operation 
which  will  be  employed  as  a  regular  part  of  the  management, 
particularly  in  plantations.  Where  pruning  is  to  be  em- 
ployed, it  may  be  possible  to  lower  planting  costs  by  use  of  a 
wider  spacing  in  the  plantations  than  could  be  employed  if 
dependence  had  to  be  placed  upon  natural  pruning  for  the 
production  of  clear  stems.^ 

REFERENCES 

1.  Knapp,  Frederick  B.  Silviculture  of  White  Pine  (Pinus  strobus). 
Bulletin  106,  Massachusetts  Forestry  Association. 

2.  FROTfflNGHAM,  E.  H.  White  Pine  under  Forest  Management.  Bulletin 
13,  United  States  Department  of  Agriculture,  1914,  pp.  38-39. 

Fisher,  R.  T.    The  Yield  of  Volunteer  Growth  as  affected  by  Improvement 

Cutting  and  Early  Weeding.     Journal  of  Forestry,  Vol.   16,   1918,  pp. 

493-506. 
Illick,  J.  S.     Sandy  Ridge  Improvement  Cutting.     Journal  of  Forestry,  Vol. 

15,  1917,  pp.  104-105. 
NiSBET,  J.     Studies  in  Forestry.     Oxford,  1894.     Pp.  203-209. 
Retan,  G.  a.     Note  on  an  Improvement  Cutting.     Forestry  Quarterly,  Vol. 

14,  1916,  pp.  777-778. 
SCHLICH,  W.     Manual  of  Forestry.    4th  edition.    London,  1910.     Pp.  298-303. 


CHAPTER  XII 
METHODS   OF  CONTROLLING  CUTTINGS 

In  silvicultural  operations,  including  both  reproduction  and 
intermediate  cuttings,  rarely  are  all  the  trees  on  any  large 
area  removed  at  one  time. 

The  felling  and  removal  of  the  trees  ordinarily  falls  into  the 
hands  of  a  lumberman  who  may  have  bought  the  timber  or 
contracted  to  log  it.  His  interests  lie  in  logging  the  timber  as 
cheaply  as  possible  without  much  attention  to  preserving  the 
trees  (from  the  reproduction  stage  up  to  mature  timber)  which 
are  to  be  left  on  the  area.  Under  the  circumstances  it  is  es- 
sential that  the  forester  devise  means  to  control  the  work  of 
the  operator  to  the  extent  of  preventing  the  cutting  or  destruc- 
tion of  trees  which  should  remain. 

Two  methods  are  available:  either  control  through  in- 
spection or  control  through  marking  of  the  trees. 

Control  through  Inspection.  —  Definite  instructions  as  to 
the  character  of  cutting  desired  can  be  given  to  the  man  in 
charge  of  logging  the  area  and  his  work  controlled  by  inspec- 
tion of  the  operations.^  Control  by  inspection  has  the  ad- 
vantage of  leaving  more  responsibility  with  the  operator 
who  may  be  sensitive  to  having  his  authority  curtailed.  If 
the  men  in  charge  of  the  logging  are  in  sympathy  with  the 
silvicultural  viewpoint  good  results  may  be  secured  by  this 
method.  Otherwise  it  will  be  difficult  to  accomplish  even  the 
minimum  silvicultural  requirements.  Much  depends  on  the 
frequency  and  carefulness  of  the  inspections,  particularly 
during  the  first  season. 

204 


CONTROL  THROUGH   MARKING   OF  THE   TREES         205 

Control  through  Marking  of  the  Trees.  —  This  is  accom- 
plished by  designation  (usually  marking)  of  either  the  trees 
to  be  cut  or  of  those  to  be  left.  The  operator  is  responsible 
only  for  the  work  of  removing  the  designated  trees  with  due 
care  for  those  left  standing,  their  selection  falling  under  the 
province  of  the  silviculturist.  Satisfactory  silvicultural  re- 
sults are  more  lilcely  to  follow  than  when  dependence  is 
placed  upon  inspection  alone.  Woolsey^  states  that  "the 
actual  selection  of  individual  trees  can  lose  or  save  many  hun- 
dreds of  dollars  in  each  miUion  feet  marked."  The  method 
of  marking  should  be  employed  wherever  there  is  any  doubt 
about  securing  satisfactory  results  through  the  control  by 
inspection.  The  necessity  for  care  to  avoid  unnecessary  dam- 
age to  standing  trees'  on  the  part  of  the  logger  still  exists.  In 
fact  his  attitude  must  be  one  of  sympathetic  cooperation  in 
the  silvicultural  plan  if  the  best  results  are  to  be  attained. 
There  is  less  opportunity  allowed  him  for  seriously  interfering 
with  the  style  of  cutting.  As  operators  gain  experience  in 
making  cuttings  in  the  practice  of  silviculture  the  tendency 
will  be  for  theni  to  prefer  the  method  of  marking  rather  than 
control  by  inspection  alone,  because  of  the  fact  that  the 
marking  method  relieves  them  of  considerable  responsibihty 
and  allows  their  attention  to  be  centered  upon  the  logging 
end  of  the  work.  Inspection  is  necessary  under  the  marking 
method  to  see  that  the  cutting  is  properly  executed,  but  the 
whole  success  of  the  method  does  not  so  vitally  depend  upon 
frequent  and  close  inspection  as  under  the  first  method. 

Either  the  trees  to  be  cut  or  those  which  are  to  remain 
may  be  marked.  The  relative  number  of  trees  to  be  cut  or 
left  is  instrumental  in  determining  which  of  the  two  classes 
should  be  marked.  When  relatively  few  trees  are  to  be  cut 
it  is  cheaper  to  mark  the  trees  to  come  out,  while  if  this  condi- 
tion is  reversed,  the  trees  to  remain  are  marked.     Where  an 


2o6  METHODS  OF  CONTROLLING  CUTTINGS 

area  is  to  be  cut  clear,  simply  marking  the  boundaries  of  the 
area  so  treated  is  sufficient. 

If  the  trees  to  be  cut  are  marked  a  blaze  going  through  the 
bark  into  the  wood  is  the  common  designation.  The  blaze 
is  made  on  the  trunk  at  a  convenient  height  above  ground, 
approximately  breast-high,  so  as  to  be  readily  seen,  or  else  is 
placed  on  a  root  swelling  or  on  the  trunk  so  low  as  to  appear 
on  the  side  of  the  cut  stump. 

The  advantage  of  having  the  blaze  placed  on  the  stump  is 
that  it  serves  as  an  excellent  check  upon  the  operator's  work. 
Two  blazes  may  be  placed  on  the  tree,  one  where  it  can  be 
readily  seen  and  the  other  on  the  stump.  The  tendency  is 
toward  the  reduction  of  expense  by  the  use  of  only  the  stump 
bkze. 

A  plain  blaze  is  of  little  use  as  a  check  on  the  operator  be- 
cause it  may  be  difficult  to  determine  by  whom  such  a  blaze 
was  made.  For  this  reason  it  is  customary  to  stamp  a  letter 
or  symbol  on  the  blaze. 

An  axe  is  the  marking  tool  commonly  utilized.  Where 
the  blazes  are  to  be  stamped,  a  special  marking  axe  is  em- 
ployed with  the  desired  letter  or  symbol  placed  on  the  head. 

Marking  with  blazes  trees  which  are  to  be  retained  is  not 
advisable,  due  to  the  possibility  of  insects  or  fungi  obtaining 
access  to  the  tree  through  the  wounds.  This  is  a  reason 
why  it  may  be  desirable  to  mark  the  trees  to  be  cut  even 
though  they  may  outnumber  those  left. 

Where  it  is  desired  to  designate  the  trees  to  remain,  paint 
often  is  employed.  In  applying  paint  care  must  be  taken  to 
remove  the  loose  bark  before  the  paint  is  put  on.  Some- 
times a  spot  of  paint  is  placed  on  the  trunk  and  stump  or  a 
ring  painted  around  the  tree.  As  a  check  on  the  cutting, 
paint  is  less  effective  than  stamped  blazes  because  it  is  more 
easily  counterfeited. 


CONTROL  THROUGH   MARKING  OF  THE   TREES 


207 


Marking  is  not  an  expensive  operation,  costing  only  a  few 
cents  per  thousand  feet  board  measure.  The  cost  is  figured 
per  thousand  feet  board  measure  of  timber  cut,  and  depends 
primarily  upon  the  size  of  the  timber,  amount  cut  per  acre, 
topographic  and  surface  conditions  of  the  area,  and  density 
of  the  underbrush  and  young  growth.  A  stand  containing 
individual  trees  of  large  size,  in  which  a  heavy  cutting  is 
made,  on  level  land  free  from  underbrush,  reproduction,  rocks 
or  other  obstructions  will  cost  less  per  thousand  feet  cut  than 
when  conditions  are  reversed. 

The  system  of  marking  suggested  for  use  in  connection 
with  each  of  the  various  kinds  of  reproduction  and  intermediate 
cuttings  is  indicated  in  the  table  below : 


Character  of  cutting 


Reproduction  cuttings: 
Clearcutting  method . 

Seed  tree  method.  .  . . 


Shelterwood  method: 
Preparatory,  seed  and 
removal  cuttings. . . . 
Final  cutting 

Selection 

Coppice 

Polewood  coppice: 

First  cutting 

Final  cutting 

Coppice  with  standards . 


System  of  marking 


Mark  the  boundaries  of  the  area  to  be  cut 
clear. 

The  seed  trees  which  are  to  remain  should 
be  designated  in  such  a  manner  as  not 
to  cause  wounds.  Paint  is  excellent  for 
this  purpose.  Marking  the  seed  trees 
will  cost  less  than  marking  all  the  trees 
to  be  cut. 


Mark  all  trees  to  be  cut. 

Mark  the  boundaries  of  the  area  on  which 

the  final  cutting  is  to  be  made. 
Mark  all  trees  to  be  cut. 
Mark  the  boundaries  of  the  area  to  be  cut 

clear. 


Mark  all  trees  to  be  cut. 

Mark  the  boundaries  of  the  area  on  which 

the  final  cutting  is  to  be  made. 
Mark  with  paint,  the  young  standards  to 

be  retained  when  the  coppice  is  cut. 

Mark  all  trees  to  be  removed  among  the 

other  standard  classes. 


208 


METHODS  OF  CONTROLLING  CUTTINGS 


Character  of  cutting 


System  of  marking 


Intermediate  cuttings: 
Cleanings 

Liberation  cuttings .  .  . 

Thinnings 

Improvement  cuttings 
Salvage  cuttings 

Severance  cuttings 

Pruning 


The  selection  of  the  vines,  shrubs  and 
trees  to  be  removed  is  made  by  the 
choppers  as  the  operation  proceeds. 
Should  be  closely  supervised  or  else  be 
done  by  men  skilled  in  the  operation. 

Mark  the  trees  to  come  out,  or  leave  selec- 
tion to  the  choppers  as  the  work  pro- 
ceeds. 

Mark  the  trees  to  come  out. 

Mark  the  trees  to  come  out. 

Mark  the  trees  to  come  out.  Where  trees 
to  be  removed  are  entirely  dead  or  se- 
verely injured  they  can  be  selected  by 
the  choppers  as  the  work  proceeds. 

Mark  the  boundaries  of  the  strip  to  be  cut 
clear. 

Mark,  in  such  a  manner  as  not  to  cause 
wounds,  the  trees  to  be  pruned. 


Marking  Rules.  —  Marking  rules  in  their  simplest  form 
comprise  a  set  of  instructions  for  marking  timber.  To  be  of 
practical  use  they  must  refer  specifically  to  a  single  species 
or  to  a  single  forest  type  and  usually  to  a  given  forest 
area. 

Marking  rules  have  been  used  principally  by  the  United 
States  Forest  Service  in  their  pubHcations  concerning  various 
commercial  trees  and  in  the  appHcation  of  silviculture  in  the 
national  forests.     See  references  at  end  of  chapter. 

Such  rules  may  range  from  simple  instructions  as  to  the 
classes  of  trees  to  be  marked  up  to  statements,  summarizing 
the  important  silvical  characteristics  of  the  species  and 
outlining  the  methods  of  reproduction  and  treatment 
throughout  the  rotation,  to  be  used  for  the  given  trees  or 
type. 

Marking  rules  are  intended  primarily  for  the  assistance  of 
the  forest  officers  in  charge  of  the  marking  on  timber  sales. 
If  only  one  kind  of  cutting,  such  as  a  Grade  C  thinning  or  a 


MARKING  RULES  209 

clearcutting  for  reproduction,  was  required  uniformly  over 
the  area  very  brief  instructions  would  suffice.  This  is  not  the 
situation  which  prevails  on  the  national  forest  sale  areas  or 
elsewhere,  except  in  small  stands.  Usually  on  the  area  to 
be  operated  at  one  time  there  will  be  several  stands,  or  at  least 
great  diversity  of  conditions  within  the  one  stand,  which 
make  necessary  a  variety  of  different  cuttings  all  combined 
in  a  single  operation.  To  intelhgently  mark  such  a  stand 
requires  information  as  to  all  phases  of  the  silvicultural  plan 
of  management  for  the  tree  and  type  concerned. 

Marking  rules  when  most  highly  developed  supply  the 
necessary  information  in  concise  form,  and  are  in  fact  sum- 
marized plans  of  silvicultural  inanagement.  It  is  desirable 
that  such  marking  rules  or  silvicultural  plans  be  drawn  up  for 
all  species  of  commercial  importance. 

One  of  the  best  examples  of  this  type  of  marking  rules  has 
been  issued  by  the  office  of  Silviculture,  in  District  I  of  the 
United  States  Forest  Service,  for  stands  of  the  Western 
White-Pine  type  on  the  Coeur  d'Alene  National  Forest  under 
date  of  January  15,  1917.^ 

This  set  of  marking  rules  is  of  sufficient  general  interest  as 
a  model  of  what  should  be  included  as  to  merit  the  brief 
resume  which  is  here  given.  The  sentences  in  itahcs  are 
taken  verbatim  from  the  original  article. 

Marking  Rules  for  Stands  of  the  Western  White-Pine  type  on 
the  Cceur  d'Alene  National  Forest.     January  15,  1917. 

Part  I 

Classification  of  Western  White-Pine  Stands.  —  Evidently 
based  on  composition  and  form  of  stand,  age,  size  and  condi- 
tion of  the  trees.  The  stands  are  divided  into  two  main 
divisions  with  a  total  of  five  subdivisions. 


2IO  METHODS  OF  CONTROLLING  CUTTINGS 

Part  II 

Objects  of  Marking.  —  Contains  a  statement  of  the  mark- 
ing rules  for  the  Western  White-Pine  type  as  a  whole  issued 
by  H.  S.  Graves,  Forester,  in  December,  1916. 

These  rules  outKne  the  general  policy  of  marking  but  are 
not  definite  enough  for  application  on  individual  areas  with- 
out supplemental  instructions  from  the  District  Office. 

The  objects  of  marking  for  each  of  the  subdivisions  estab- 
Hshed  under  the  classification  into  stands  are  stated  in  a 
general  way  and  then  full  details  given  for  their  application, 
forming  the  silvicultural  plan  of  management  for  the  type. 
Intermediate  and  reproduction  cuttings,  provisions  for  the 
start  and  development  of  reproduction,  the  removal  of  unde- 
sirable species  and  slash  disposal  receive  consideration. 

Part  III 

Scientific  facts  concerning  the  life  Jdstory  of  western  white 
pine  which  have  a  hearing  upon  marking.  The  subjects  treated 
are  the  following: 

Reproduction  after  cutting,  Germination  of  seed,  Development 
after  germination,  Seed  production.  Seed  production  from  indi- 
vidual trees,  Seed  distribution,  Competitive  strength,  Recovery 
after  thinning.  Fire  resistance,  Windfirmness,  Relation  of  size 
and  age  and  Associate  species. 

Part  IV 

General  Treatment  of  Associate  Species  of  White  Pine.  — 
Brief  directions  as  to  the  treatment  of  trees  of  the  eight  asso- 
ciate species. 

Part   V 

Contains  a  statement  to  the  effect  that  these  marking  rules 
are  of  general  application  to  the  type  and  more  specific  rules 


CONTROL  OF  WASTE  211 

should  be  drawn  up  for  each  logging  chance.  The  procedure 
of  making  such  specific  rules  involves  the  preparation  of  a 
type  and  stand  map  and  the  gathering  of  data  in  reference  to 
the  size,  age  and  condition  of  the  timber. 

Control  of  Waste  and  Destruction  in  Logging.  —  Waste  and 
destruction  of  timber  in  the  logging  is  Hkely  to  occur  in  any 
operation.  From  the  silvicultural  standpoint  such  losses  are 
important  because  they  decrease  the  yield  from  the  area  at 
the  present  cutting,  and  may  lessen  the  possible  production 
in  the  future.  The  waste  and  destruction  may  be  classified 
under  the  following  headings: 

(a)  Material  left  in  the  tops,  through  failure  to  utilize  the 
trunk  up  to  the  minimum  merchantable  top  diameter. 

(b)  Material  left  in  the  stumps  through  failure  to  cut  the 
stumps  to  the  lowest  possible  limit. 

(c)  Material  left  in  windfalls  and  dead  trees  through  failure 
to  utilize  the  merchantable  portions  of  such  trees. 

(d)  Destruction  of  the  unmerchantable  growing  stock  either 
for  material  to  use  in  the  logging  operations  for  skids,  cordu- 
roy roads,  bridge  construction,  etc.,  or  in  order  to  facilitate 
the  logging  work. 

Nowadays  waste  under  the  first  three  headings  is  consid- 
ered evidence  of  an  inefficient  logging  operation.  As  a  busi- 
ness proposition  the  lumberman  may  be  expected  to  remedy 
this  defect  in  his  operations,  so  soon  as  it  comes  to  his  atten- 
tion, without  necessarily  adopting  the  practice  of  silviculture. 
Close  utilization  of  material  in  tops,  windfalls  and  dead  trees 
is  indirectly  of  silvicultural  benefit  by  reducing  the  amount  of 
inflammable  material  in  the  forest  and  by  removing  trees 
which  might  harbor  destructive  insects  and  fungi. 

In  judging  whether  material  is  being  wasted  in  high  stumps, 
big  tops  and  dead  and  down  trees  careful  consideration  must 


212  METHODS  OF  CONTROLLING  CUTTINGS 

be  given  to  what  constitutes  merchantability  in  that  particular 
locality.  Local  conditions  governing  the  logging  operations 
or  existing  in  the  available  markets  may  neccessitate  two 
different  sets  of  standards,  as  to  minimum  top  diameters, 
maximum  height  of  stumps,  and  extent  to  which  dead  and 
down  material  can  be  utiUzed,  for  operations  only  a  few  miles 
apart. 

Destruction  of  the  unmerchantable  growing  stock  is  of  more 
vital  silvicultural  importance  than  the  other  classes  of  waste. 
Reduction  in  the  growing  stock,  from  reproduction  right  on 
up  to  trees  just  under  merchantable  size,  is  Kkely  to  result  in  a 
lower  production  in  the  future  crops.  The  lumberman,  as 
such,  rarely  is  interested  in  saving  the  unmerchantable  grow- 
ing stock  at  the  expenditure  of  any  trouble  or  actual  outlay. 
Where  unmerchantable  trees  will  reach  merchantable  size 
within  a  few  years  he  may  see  a  fairly  early  profit  in  saving 
such  trees,  but  in  reproduction  and  young  growth  as  a  whole 
he  has  no  interest.  Intention  to  practice  silviculture  must 
exist  if  the  unmerchantable  growing  stock  is  to  receive  pro- 
tection. 

A  certain  portion  of  the  unmerchantable  growing  stock  may 
have  to  be  sacrificed  in  the  logging  operation.  This  will  de- 
pend upon  the  difficulties  of  logging,  the  quantity  and  location 
of  the  young  trees  and  the  intensity  of  the  silviculture.  The 
proportion  which  must  be  sacrificed  should  be  determined  in 
advance  of  the  cutting  and  destruction  kept  within  prescribed 
limits. 

Destruction  of  the  unmerchantable  growing  stock  was 
stated  on  page  211  to  be  carried  on  either  for  material  to  use 
in  the  logging  operations  or  to  facilitate  these  operations. 

Material  for  use  in  logging  operations  is  taken  from  the 
young  trees  for  skids,  construction  of  skidways,  corduroy 
roads,  and  other  logging  requirements.     This  material  is  essen- 


REFERENCES  213 

tial  but  oftentimes  can  be  secured  with  little  if  any  added 
cost  from  inferior  species,  tops  or  cull  material. 

In  facilitating  logging  operations,  seedlings  and  small  trees 
are  cut  if  interfering  with  the  choppers,  sawyers,  or  skidding 
crews,  while  merchantable  trees  are  apt  to  be  dropped  in  the 
direction  of  their  easiest  fall,  regardless  of  the  young  growth 
which  may  thereby  be  smashed.  With  practice  on  the  part 
of  the  operators  a  large  proportion  of  this  class  of  destruction 
can  be  eliminated. 

Destruction  of  unmerchantable  growing  stock  is  most  likely 
to  occur  in  unevenaged  stands  where  the  young  and  the  old 
trees  are  intermixed  on  the  same  area.  Under  the  clearcut- 
ting  method  there  is  little  temptation  to  injure  the  younger 
age  classes  in  the  logging  operations. 

Frequent  inspection  systematically  conducted  and  supple- 
mented by  itemized  reports  with  reference  to  the  waste  of 
material  or  destruction  of  unmerchantable  growing  stock 
furnishes  the  best  method  of  control. 


REFERENCES 

1.  Cary,  A.  Practical  Forestry  on  a  Spruce  Tract  in  Maine.  Circular  131, 
Forest  Service,  United  States  Department  of  Agriculture,  Washington,  1907, 
p.  10. 

2.  WooLSEY,  T.  S.,  Jr.  Marking  Western  Yellow  Pine.  Forestry  Quar- 
terly, Vol.  7,  1909,  p.  271. 

3.  Marking  Rules  for  Stands  of  the  Western  White-Pine  Type  on  the 
Coeur  d'Alene  National  Forest.  January  15,  191 7,  pp.  878-885  included  in 
an  article  entitled  "Development  in  the  Marking  of  Western  White  Pine 
{Pinus  monticola)  in  Northern  Idaho"  prepared  by  C.  K.  McHarg,  J.  Kittredge 
and  J.  F.  Preston,  Journal  of  Forestry,  Vol.  XV,  1917,  pp.  871-885. 

Carter,  E.  E.  The  Silvicultural  Results  of  Marking  Timber  on  the  National 
Forests.  Proceedings  of  the  Society  of  American  Foresters,  Vol.  Ill,  1908, 
pp.  18-28. 

Frothingham,  E.  H.  Principles  Governing  the  Marking  of  Northern  Hard- 
woods in  National  Forest  Timber  Sale  Practice  in  the  White  Mountains. 


\  ]\IETHODS   OF   CONTROLLING   CUTTINGS 

Included  in,  The  Northern  Hardwood  Forest:  Its  Composition,  Growth 
and  Management.  Bulletin  285,  United  States  Department  of  Agricul- 
ture, Washington,  1915,  pp.  42-44. 

Mason,  D.  T.  Marking  Rules  for  Lodgepole  Pine  Stands  on  the  Deerlodge 
National  Forest.  Included  in,  UtiUzation  and  Management  of  Lodgepole 
Pine  in  the  Rocky  Mountains.  Bulletin  234,  United  States  Department 
of  Agriculture,  Washington,  191 5,  pp.  25-28. 

Meinecke,  E.  p.  Forest  Pathology  in  Forest  Regulation.  Bulletin  275, 
U.  S.  Department  of  Agriculture,  Washington,  1916,  pp.  57-58. 

MuNGER,  T.  T.  Instructions  for  Marking  Timber  in  the  Yellow  Pine  Region, 
District  6.  Included  in,  Western  Yellow  Pine  in  Oregon.  Bulletin  418, 
United  States  Department  of  Agriculture,  Washington,  191 7,  pp.  46-47. 

Weir,  James  R.,  and  Hubert,  Ernest  E.  Pathological  Marking  Rules  for 
Idaho  and  Montana.     Journal  of  Forestry,  Vol  XVII,  1919,  pp.  666-681. 


CHAPTER  XIII 
SLASH  DISPOSAL 

Definition.  —  Slash  is  understood  to  include  all  the  debris 
left  in  the  forest  as  the  result  of  a  cutting  (or  other  agencies) 
and  comprises  the  tops,  branches  and  unutilized  portions  of 
the  trees  cut  together  with  other  trees  uprooted  or  broken 
off  in  the  process  or  as  a  consequence  of  the  logging.  A 
broad  definition  of  the  term  includes  also  dead  trees  and 
windfalls  on  the  ground  previous  to  the  logging.  Slash  is 
created  not  only  as  a  result  of  cutting,  but  also  as  a  result  of 
other  destructive  agencies,  the  most  important  being  fire, 
and  wind,  which  may  cause  the  death  and  overthrow  of  a 
large  portion  of  the  stand. 

Silvicultural  Effects  of  Slash.  —  Slash  as  defined  above 
consists  of  such  a  variety  of  material  that  it  is  best  to  divide 
the  total  into  several  classes  of  material  before  discussing  its 
silvicultural  effect. 

Classification  of  slash: 

{a)  Material    which    decays    rapidly.     Includes    small 

branches  and  tops  and  foliage. 
{h)  Large  branches  and  tops, 
(c)   Logs  and  unused  portions  of  the  bole. 

The  relative  amounts  of  the  different  classes  of  material  on 
a  given  area  show  wide  variations  depending  primarily  upon 
the  conditions  governing  utihzation  of  forest  products.  With 
intensive  utilization  the  slash  that  remains  may  consist  only 

215 


2l6  SLASH  DISPOSAL 

of  foliage  and  small  branches.     In  rare  cases  even  this  mate- 
rial may  find  utilization  as  brushwood. 

Slash  may  be  distinguished  as  originating  from  either  conif- 
erous or  broadleaf  species  of  trees.  Of  the  two  the  coniferous 
slash  makes  the  denser  cover,  remains  sound  longer  and  on 
the  whole  is  a  greater  menace  than  hardwood  slash.  The 
latter  often  makes  an  unsightly  tangle  loosely  occupying 
considerable  space  but  is  not  potentially  so  much  a  source  of 
danger  as  the  lower  lying,  more  compact  coniferous  slash. 
Hardwood  slash  .absorbs  moisture  faster,  and  goes  to  pieces 
more  quickly.  This  process  may  be  so  rapid  as  not  to  justify 
any  expenditure  for  hastening  the  result. 

For  these  reasons  disposal  of  coniferous  slash  is  more  com- 
monly undertaken. 

The  silvicultural  effects  of  slash  in  a  narrow  sense  may  be 
restricted  to  the  direct  effect  upon  the  soil  and  reproduction. 
Under  this  interpretation  slash  disposal  has  separate  and 
distinct  silvicultural,  fire,  entomological  and  pathological  as- 
pects. As  a  matter  of  fact  the  production  of  better  tree  crops 
is  the  basis  of  the  forester's  interest  in  treatment  of  slash. 
Forest  fires,  insects  and  fungi  are  destructive  agencies  whose 
action  is  directly  and  primarily  to  affect  production  of  tree 
crops.  Hence  the  influence  of  slash  upon  these  destructive 
agencies  is  of  silvicultural  importance  and  together  with  its 
more  direct  influence  upon  soil  and  reproduction  is  properly 
combined  under  the  silvicultural  effects  of  slash. 

Slash  in  Relation  to  the  Soil.  —  The  effect  of  slash  upon 
forest  soil  is  beneficial.  It  prevents  erosion  and  land-slides 
by  holding  the  litter  and  soil  in  place  and  by  mechanically 
obstructing  the  movement  of  water  and  soil.  Through  the 
process  of  decay  it  adds  to  the  organic  matter  in  the  soil  and 
as  a  consequence  should  tend  to  increase  its  productivity. 
Where  an  excess  supply  of  undecomposed  litter  covers  the 


SILVICULTURAL  EFFECTS  OF  SLASH  217 

ground  the  beneficial  influence  of  slash  is  at  a  minimum.  On 
bare  soils  and  on  steep  slopes  at  high  altitudes  the  protective 
value  of  slash  is  greatest. 

Slash  in  Relation  to  Reproduction.  —  Slash  exerts  an  influ- 
ence upon  reproduction  sometimes  beneficial  and  sometimes 
unfavorable,  depending  upon  the  amount  and  character  of 
the  slash  and  the  silvical  conditions  in  the  individual  case. 
Where  slash  is  so  abundant  as  to  occupy  a  considerable  por- 
tion of  the  area  it  is  certain  to  have  an  important  relation  to 
reproduction. 

Its  beneficial  effect  is  to  encourage  the  start  and  early- 
development  of  reproduction.  This  may  be  accomphshed: 
(i)  By  the  conservation  of  the  moisture  in  the  surface  soil 
through  the  protection  afforded  by  the  slash  against  sun  and 
wind,  (2)  By  the  creation  of  desired  seedbed  conditions 
through  shading  and  through  the  increase  in  humus  and  litter 
(derived  from  the  foliage  of  the  felled  trees),  (3)  By  the 
protecting  shade  afforded  young  plants,  and  (4)  By  the  me- 
chanical protection  given  the  seedHngs  against  the  trampling 
and  browsing  of  animals. 

The  harmful  influence  of  slash  upon  reproduction  is  its 
action  as  an  obstacle  to  germination  or  to  early  development 
of  the  young  plants.  Slash,  where  it  hes  thickly,  may  mechan- 
ically stop  the  growth  of  reproduction  which  started  previous 
to  the  cutting.  Sufficient  heat  for  germination  of  seeds  to 
take  place  may  be  lacking  due  to  the  amount  of  slash,  or  the 
seedbed  created  may  be  unfavorable.  If  germination  takes 
place  there  may  be  lack  of  light  under  the  slash  to  insure 
survival  of  the  reproduction. 

Slash  in  Relation  to  Forest  Fires.  —  Unquestionably  slash 
is  dangerous  from  the  fire  standpoint  for  it  is  one  of  the  most 
important  sources  of  inflammable  material.  In  addition  to 
the  slash  the  fitter,  ground  cover,  underbrush,  fiving  trees  and 


2l8  SLASH  DISPOSAL 

snags  or  standing  dead  trees  furnish  quantities  of  inflamma- 
ble material.  Where  no  cuttings  or  extensive  damage  by  fire, 
insects  or  other  agencies  have  occurred  the  slash  provides  the 
larger  portion  of  the  potential  fuel.  The  foliage  and  the  small 
branches  are  easily  ignited  and  may  burn  rapidly  but  the 
larger  Hmbs  and  logs  cannot  be  kindled  so  quickly  or  burn  so 
rapidly;  although  when  once  started  they  will  create  more 
heat,  burn  for  a  longer  time  and  in  general,  other  conditions 
being  equal,  make  a  severer  fire  than  could  occur  on  the  same 
area  if  without  slash.  With  conifers  which  retain  their  foHage 
for  some  time  after  felling,  the  slash  may  be  easily  ignited  for 
several  months  by  simply  touching  a  lighted  match  to  the 
foliage.  This  is  particularly  the  case  on  heavily  cut  areas 
where  the  cutting  itself  results  in  opening  the  stand  to  the 
drying  action  of  sun  and  wind  thereby  increasing  the  inflam- 
mabiHty  of  the  fuel. 

Ordinarily  the  Utter  or  ground  cover  provides  that  portion 
of  the  available  fuel  which  is  most  easily  ignited.  A  fire  is 
apt  to  start  in  this  material  (even  on  areas  covered  with  slash) 
and  then  spread  quickly  to  the  slash  itself.  The  larger  mate- 
rial included  in  the  slash,  when  once  set  on  fire,  may  make  an 
exceptionally  serious  conflagration,  which  may  gain  such  im- 
petus as  to  sweep  through  adjacent  green  timber. 

The  prevalence  of  fires  on  cutover  areas  should  not  be  attri- 
buted wholly  to  the  presence  of  slash  Grasses  and  weeds  may 
spring  up  after  heavy  cuttings  and  provide  fuel  for  the  flames. 

Besides  furnishing  a  large  part  of  the  inflammable  material, 
slash  renders  the  fighting  of  fires  difficult  and  dangerous.  A 
slash  covered  area  cannot  be  traversed  quickly  and  the  fighters 
may  be  caught  if  in  the  path  of  the  fire.  More  labor  is  re- 
quired to  prepare  hnes  for  checking  the  fire  and  it  may  be 
impossible  to  use  methods  of  control  which  on  areas  free  from 
slash  would  be  feasible. 


SILVICULTURAL  EFFECTS  OF   SLASH  219 

Slash  in  Relation  to  Insects.  —  Insects,  particularly  bark 
beetles,  find  in  the  slash  a  place  where  they  may  breed  and 
develop  and  then  migrate  to  adjacent  Hving  timber.  Newly 
cut  slash  offers  favorable  opportunities  for  strong  swarms  of 
insects  to  develop  until  they  are  able  to  attack  successfully 
Hving  timber.  The  destructive  insects  breed  almost  exclu- 
sively in  the  tops,  logs  and  larger  limbs  included  among  the 
slash  and  not  in  the  very  small  limbs. ^  Portions  of  the  tree 
from  which  the  bark  has  been  removed  do  not  furnish  favor- 
able breeding  grounds  for  the  insects  destructive  to  live 
timber.  There  are  various  insects  which  work  in  dry  wood 
and  in  rotting  logs,  but  the  insects  developing  in  slash,  which 
are  to  be  feared  as  a  menace  to  standing  timber,  will  breed  in 
the  freshly  cut  logs  and  Hmbs  having  the  bark  on.  It  should 
be  recognized  that  not  all  the  destructive  insects  found  on 
cutover  land  have  necessarily  developed  in  the  slash.  Some 
may  have  been  bred  in  stumps  or  in  standing  dead  and  dying 
trees. 

Slash  in  Relation  to  Fungi?'  ^  —  The  slash  acts  as  host  for 
a  variety  of  fungi  all  of  which  are  beneficial  in  hastening  decay 
of  the  slash.  Sporophores  may  be  produced  on  the  slash  and 
from  them  spores  scattered  which  in  the  case  of  many  dan- 
gerous species  of  fungi  cause  infection  of  standing  trees. ^ 
Those  fungi  which  are  most  virulent  and  destructive  to  Hving 
trees  develop  principally  in  the  larger  pieces  of  the  slash. 
Their  spores  may  be  carried  many  miles  to  affect  Hving  trees 
distant  from  the  cutover  area. 

In  warm  and  humid  regions  favorable  to  the  development 
of  fungi,  the  danger  to  trees  on  the  area,  and  in  the  adjoining 
forest,  of  infection  by  destructive  diseases  developing  first  in 
the  slash  is  very  great. 

Slash  in  Relation  to  Forest  Esthetics.  —  From  the  stand- 
point of  forest  aesthetics  the  presence  of  slash  is  a  nuisance. 


220  SLASH  DISPOSAL 

It  spoils  the  appearance  of  the  forest.  There  are  many- 
places  where  this  factor  has  little  weight.  In  connection 
with  the  handling  of  public  forests  the  idea  of  partial  utilization 
and  development  for  recreational  purposes  is  gaining  ground. 
This  means  that  increasing  attention  will  be  given  to  forest 
aesthetics. 

Methods  of  Slash  Disposal.  —  Methods  of  such  widely 
diverse  character  have  been  developed  for  treatment  of  slash 
as  to  meet  the  requirements  of  all  conditions  encountered  in 
the  field.  The  principal  methods  for  treating  slash  are  dis- 
cussed here. 

Disposal  of  Slash  by  Piling.  —  This  requires  the  placing  of 
the  slash  in  piles  instead  of  leaving  it  scattered  over  the  area. 
The  logger  in  the  ordinary  course  of  his  work,  to  keep  the  slash 
from  hindering  operations,  throws  it  into  loose  piles  or  wind- 
rows. This  is  essential  where  the  amount  of  slash  is  large  and 
the  timber  is  removed  from  the  felling  area  by  animal  power. 
Such  treatment  should  not  be  confused  with  a  piling  method 
under  which  the  slash  is  piled  systematically  and  the  area  it 
occupies  greatly  reduced. 

Before  slash  can  be  piled  the  large  tops  and  limbs  must  be 
cut  up  and  reduced  to  small  enough  size  to  be  easily  handled 
and  closely  piled.  The  piles  should  be  small  and  compact. 
Large  piles  are  more  dangerous  to  burn  than  small  ones  and 
usually  require  the  brush  to  be  carried  farther.  Loose  piles 
are  difficult  to  burn  cleanly  and  occupy  too  much  space. 
Piles  may  be  made  circular  or  rectangular  in  form.  If  rect- 
angular, stakes  should  be  set  and  the  slash  packed  in  tightly 
between  the  stakes. 

Mitchell^  states:  ''Round  piles  usually  burn  better  than 
long  ones,  since  they  are  ordinarily  more  compact.  .  .  .  Ex- 
perience has  also  shown  that  to  burn  to  the  best  advantage 
the  height  of  a  pile  should  equal,  if  not  exceed,  its  diameter, 


METHODS  OF  SLASH  DISPOSAL  221 

and  that,  as  far  as  possible,  the  butts  of  the  Hmbs  should  be 
placed  toward  the  center  of  the  pile." 

It  is  frequently  unnecessary  and  often  impracticable  with- 
out considerable  expense  to  place  the  entire  volume  of  the 
slash  in  piles.  The  more  inflammable  portion,  consisting  of 
the  small  branches  with  such  twigs  and  fohage  as  are  retained, 
should  be  piled  and  in  addition  such  of  the  larger  branches 
and  portions  of  the  bole  as  are  conveniently  located  with 
reference  to  the  piles  or  may  be  needed  to  weight  down  or 
keep  the  piles  from  being  flattened  out  by  heavy  snows. 

Most  of  the  large  branches,  cull  logs,  windfalls  and  other 
unutiHzed  trees  are  not  put  into  the  piles,  unless  this  is  neces- 
sary to  prevent  the  breeding  of  destructive  insects.  They 
may  be  left  lying  in  contact  with  the  ground  where  they 
absorb  moisture  and  decay  more  quickly  than  if  elevated. 

Pihng  of  slash  while  the  cutting  is  in  progress  and  before 
the  logs  are  skidded  has  the  advantage  of  facilitating  this 
operation  since  the  ground  is  somewhat  cleared  of  debris. 
More  effective  results  from  labor  are  Ukely  to  be  secured  where 
the  piUng  is  a  part  of  the  logging  job  ^  and  can  be  supervised 
without  additional  expense. 

Brush  piles  should  be  located  so  as  not  to  be  in  the  way  of 
skidding  operations  and  (if  they  are  to  be  burned)  at  safe 
distances  from  reproduction  and  larger  trees.  If  the  piling  is 
not  done  until  after  the  completion  of  the  logging  many  of 
the  piles  can  be  located  in  roadways  and  yards.  Where  it  is 
desired  to  destroy  undesirable  reproduction,  underbrush  or 
trees  of  inferior  species  the  piles  should  be  located  so  as  to  kill 
this  material. 

The  method  of  piling  is  further  subdivided  depending  on 
the  final  disposition  of  the  piled  material  into  the  following 
submethods. 

{a)  Piling  and  Burning.  —  The  piles  are  burned  as  a  special 


222  SLASH   DISPOSAL 

piece  of  work  distinct  from  the  piling.  The  piles  must  be 
carefully  built  because  they  may  have  to  stand  several  months 
before  the  time  for  burning  arrives. 

During  dry  seasons  of  the  year  it  is  often  dangerous  to 
carry  on  any  slash  burning  operations.  As  a  precaution  the 
piles  made  in  such  periods  are  not  burned  until  later  and  only 
when  cHmatic  conditions  are  such  as  to  render  the  operation 
safe.  An  ideal  time  to  burn  brush  piles  is  immediately  after 
the  first  snowfall,  which  is  apt  to  be  so  light  as  not  to  prevent 
easy  burning  of  the  piles,  although  affording  protection  to 
surrounding  trees. 

Burning  of  a  large  number  of  brush  piles  is  at  best  a  risky 
operation.  There  is  the  danger  of  the  fire  becoming  uncon- 
trollable and  spreading  from  pile  to  pile  until  finally  the  fire 
has  gained  such  momentum  that  it  cannot  be  held  on  the 
cutover  area  but  spreads  into  adjacent  uncut  timber.  Repro- 
duction and  young  timber  standing  in  proximity  to  the  piles 
may  be  injured  or  destroyed  by  the  heat  of  the  fire  even 
though  it  does  not  spread  from  pile  to  pile. 

If  a  group  of  adjoining  piles  is  burned  all  at  one  time  the 
air  becomes  so  heated  and  such  a  draft  is  created  that  the 
remaining  live  trees  and  reproduction  on  the  area  may  be 
killed.  A  better  arrangement  is  to  burn  piles  here  and  there 
and  not  to  set  fire  to  the  adjacent  piles  until  those  first  lighted 
have  been  consumed.  If  a  wind  is  blowing  the  burning  should 
be  started  among  the  piles  on  the  leeward  side  of  the  cutover 
area. 

Where  a  large  number  of  brush  piles  must  be  lighted  a 
special  brush  burning  torch  is  useful.  The  torch  should  be 
rigid  and  strong  enough  to  be  thrust  into  the  piled  slash 
without  injury  to  the  handle  or  to  the  torch  proper  and  be 
capable  of  burning  for  some  time.  One  of  the  best  torches  ^ 
can  be  made  out  of  a  piece  of  pipe. 


METHODS   OF   SLASH   DISPOSAL  223 

If  the  piles  are  small  and  well  built  they  may  burn  com- 
pletely without  any  attention  after  Kghting.  Otherwise  the 
partially  consumed  piles  must  be  visited  while  still  burning 
and  "chunked  up"  by  having  the  unconsumed  brush  around 
the  edges  thrown  onto  the  fire. 

(b)  Burning  as  the  Logging  Proceeds.  —  Fires  are  started 
upon  which  the  slash  is  thrown.  The  piling  and  burning  is 
thus  accompHshed  in  one  operation. 

This  method  is  the  most  economical  from  the  standpoint 
of  the  lumberman  and  the  forester.  The  work  of  pihng  and 
burning  is  done  in  conjunction  with  the  removal  of  the  tim- 
ber. The  feUing  crews  may  do  the  work  or  special  men  may 
be  assigned  to  the  duty.  Fires  should  be  started  in  openings 
away  from  reproduction  and  young  trees.  When  a  tree  is 
limbed  out  the  branches  are  thrown  directly  upon  the  fire, 
and  do  not  have  to  be  cut  up  so  small  as  when  placed  in 
piles. 

The  actual  cost  of  burning  the  brush  is  likely  to  be  reduced 
when  conducted  in  this  manner.  This  method  is  preferable 
to  pihng  and  burning  in  a  separate  operation,  but  can  be 
employed  only  under  climatic  conditions  favorable  to  safe 
burning.  When  the  logging  is  done  in  the  hot  dry  seasons 
of  the  year  piling  and  burning  later  is  the  alternative. 

Disposal  of  Slash  by  Broadcast  Burning.  —  In  broadcast 
burning  fires  are  started  and  allowed  to  burn  over  the  area 
occupied  by  slash.  It  is  a  cheap  method  of  disposal  for  it  re- 
quires no  pihng  and  very  little  handhng  of  the  slash.  Around 
the  edges  of  the  cutover  area  firehnes  should  be  cleared  of 
slash  and  other  inflammable  material.  If  the  area  is  exten- 
sive interior  fire  lines  may  be  needed  dividing  the  area  into 
blocks.  How  large  these  blocks  should  be  will  depend  on  the 
conditions  in  each  case,  among  which  amount  and  inflamma- 
bihty  of  the  slash  and  the  difficulties  of  controlHng  the  fire  are 


224  SLASH  DISPOSAL 

of  primary  importance.  Rarely  should  the  block  be  larger 
than  forty  acres.  Should  there  be  on  the  area  any  trees  which 
it  is  desired  to  save  then  the  slash  must  be  pulled  away  from 
them. 

A  fire  hot  enough  to  consume  the  slash  is  likely  to  destroy 
all  reproduction  and  trees  on  the  area  covered  by  the  fire. 
It  may  consume  all  of  the  litter.  Broadcast  burning  some- 
times is  employed  in  connection  with  a  clearcutting  method 
depending  for  reproduction  upon  seed  stored  in  the  duff.  It 
is  then  essential  that  the  litter  which  contains  the  stored 
seed  be  protected  from  the  fire.  This  can  be  accomplished 
by  burning  at  a  time  when  the  slash  is  fairly  dry  but  the  litter, 
less  exposed  to  the  effects  of  sun  and  wind,  still  remains  wet. 
The  fire  may  burn  the  upper  portion  of  the  litter  but  not  the 
whole.     The  slash  must  be  dry  enough  to  secure  a  clean  burn. 

Broadcast  burning  is  a  dangerous  method  of  slash  disposal 
because  unless  carefully  controlled  the  fire  is  Hkely  to  gain 
momentum  and  escape  to  adjoining  timbered  areas.  For 
this  reason  the  time  of  burning  must  be  chosen  so  as  to  secure 
favorable  climatic  conditions.  The  ideal  time  for  burning 
may  be  stated  as  a  period  with  little  or  no  wind,  what  there  is 
coming  steadily  from  one  direction,  relatively  high  humidity, 
low  temperature  and  cloudy  weather  immediately  preceding 
a  period  of  rain  or  snow.  This  combination  is  difficult  to 
attain  with  certainty,  but  the  nearest  approach  to  the  ideal 
is  likely  to  be  found  by  selecting  for  the  operation  a  night  in 
the  early  spring  or  late  fall  when  there  is  a  probability  of 
rain  or  snow  to  follow. 

A  force  of  men  should  be  on  hand  to  set  the  fires  and  watch 
their  progress  and  in  addition  if  the  area  to  be  burned  over 
is  extensive  it  is  advisable  to  have  arrangements  completed 
in  advance  of  the  burning  with  a  larger  force  of  men  to  come 
out  at  once  in  case  the  fire  escapes.     The  crews  in  nearby 


METHODS   OF   SLASH   DISPOSAL  225 

lumber  camps  are  logically  the  men  for  such  an  emergency 
force. 

In  conducting  the  broadcast  burning  fires  are  set  at  several 
points  on  the  leeward  side  of  a  block  which  is  to  be  burned 
over.  The  fires  so  started  are  prevented  from  crossing  the 
fire  line  and  forced  to  burn  against  the  wind.  It  is  best  to 
burn  only  one  block  at  a  time  and  to  have  men  patrolHng  the 
cleared  lines  to  prevent  the  fire  crossing.  On  areas  where 
the  slash  was  heavy  and  contained  large  sized  cull  material  the 
fire  may  remain  smoldering  for  several  days 

Disposal  of  Slash  by  Lopping.  —  Lopping  consists  in  the 
cutting  up  of  the  slash  into  smaller  pieces.  In  order  to  have 
practical  value  the  term  must  be  made  more  definite  in  ac- 
cordance with  the  specifications  holding  in  the  given  locality. 
For  example  the  top  lopping  law  of  New  York  State  requires 
that  all  limbs  three  inches  and  over  in  diameter  be  severed 
from  the  trunk  and  that  tops  be  lopped  down  to  the  three 
inch  point. 

In  theory  lopping  is  designed  to  cut  the  slash  up  into 
pieces  of  such  size  and  shape  as  will  He  in  close  contact  with 
the  ground,  where  they  will  absorb  moisture  and  decay  more 
quickly.^ 

The  lopping  method  may  include  scattering  the  lopped  por- 
tions of  slash  so  as  to  avoid  piles  and  windrows  or  it  may 
leave  the  lopped  portions  just  as  they  He  without  further 
handling.  During  the  hauHng  out  of  the  logs  the  lopped  tops 
are  Hkely  to  be  thrown  together  into  loose  heaps.  If  a  scat- 
tering method  is  used  the  scattering  must  be  done  as  the  final 
step  after  the  logs  have  been  yarded. 

The  best  time  to  carry  on  the  lopping  is  in  connection  with 
the  trimming  of  the  bole  and  bucking  up  the  logs. 

Lopping  is  classed  as  a  cheap  method  of  slash  disposal 
compared  with  methods  involving  piHng.     This  is  not  the  fact 


226  SLASH  DISPOSAL 

in  all  cases.  Where  careful  scattering  of  the  slash  is  included 
following  the  lopping  the  cost  is  Hkely  to  be  higher  than  pihng 
and  burning.  The  cheapest  lopping  involves  no  scattering 
of  the  slash. 

The  lopping  method  improves  soil  conditions  by  allowing 
the  tops  to  decay  and  increase  the  humus  content  and  acts 
mechanically  to  prevent  erosion.  Skidding  the  logs  is  made 
easier  and  cheaper  where  the  slash  is  cut  into  small  pieces 
and  hence  easily  moved.  A  tendency  toward  closer  utiliza- 
tion is  developed,  because  where  the  bole  must  be  trimmed 
of  branches  up  to  a  small  diameter  limit  in  the  lopping  the 
operator  is  likely  to  use  more  of  the  bole  than  he  otherwise 
would.  Fire  fighting  is  easier  in  lopped  than  in  unlopped 
slash  because  of  the  ease  and  speed  with  which  the  former 
can  be  handled. 

A  strong  disadvantage  is  the  fact  that  until  the  lopped  tops 
decay  a  serious  fire  hazard  may  exist  .^  The  length  of  time 
necessary  for  the  tops  to  absorb  moisture  or  decay  sufficiently 
to  cease  being  a  fire  hazard  varies  with  the  climatic  conditions, 
the  amount  of  the  lopped  material,  and  its  position  with 
respect  to  contact  with  the  ground. 

Disposal  of  Slash  by  Pulling  the  Tops.  —  Pulling  the  tops 
consists  in  dragging  the  entire  unutilized  tops  of  the  trees  to 
positions  on  the  area  different  from  those  occupied  by  the 
tops  when  the  trees  were  felled.  The  operation  is  accom- 
pHshed  by  hitching  one  or  more  animals  to  each  top.  Tops 
are  dragged  in  cases  where  they  lie  in  dangerous  proximity  to 
standing  trees  or  reproduction  or  else  where  they  are  needed 
to  cover  spots  likely  to  be  eroded  such  as  gullies  or  slopes. 
In  some  cases  the  tops  are  of  assistance  to  reproduction  by 
affording  either  slight  shade,  the  desired  seedbed  or  protection 
from  the  trampling  or  browsing  of  animals  whom  the  tops 
keep  off.     The  pulled  tops  because  of  standing  relatively  high 


METHODS   OF   SLASH   DISPOS.\L  227 

above  the  ground  and  being  able,  when  burning,  to  carry 
flames  into  the  crowns  of  trees,  constitute  a  more  serious  fire 
menace  to  standing  trees  than  do  lopped  tops.^ 

The  method  does  not  remove  any  of  the  slash  from  the 
felling  area,  it  simply  changes  the  position  of  a  portion,  usu- 
ally a  small  proportion  of  the  material. 

Light  Burning.  —  Light  burning  is  not  a  method  of  slash 
disposal.  It  consists  in  the  annual  or  periodic  burning  over 
broadcast  of  forest  areas  before  instead  of  after  cutting  opera- 
tions. Slash  as  previously  defined  is  created  mainly  as  a 
result  of  such  operations. 

Light  burning  is  an  intentional  use  of  surface  fires  to  keep 
the  ground  free  of  the  highly  inflammable  material  which  is 
made  up  of  Htter,  ground  cover,  underbrush  and  reproduction. 

The  theory  is  that  if  such  material  is  burned  at  relatively 
frequent  intervals  a  fire,  hot  enough  to  injure  the  less  inflam- 
mable but  more  valuable  material,  namely  the  standing  tim- 
ber, cannot  start.  This  would  be  logic  did  it  not  overlook 
the  injury  to  the  productive  power  of  the  forest  caused  by 
light  burning.  It  may  be  summarized  under  the  following 
headings: 

{a)  Injury  to  the  Soil. — Light  burning  proposes  to  prevent 
the  accumulation  of  fitter  which  is  essential  for  the  produc- 
tion of  humus,  this  in  turn  being  of  vital  importance  in  main- 
taining the  physical  properties  of  the  soil  in  best  condition. 
Annual  burning  removes  the  fitter  as  fast  as  it  forms  and  has 
a  serious  effect  on  the  humus  content.  Periodic  burning  at 
intervals  of  three  to  five  years  is  nearly  as  bad,  since  it  re- 
quires several  years  for  fitter,  after  its  fall,  to  decompose  into 
humus.  Sandy  soils  with  level  topography  are  least  injured, 
while  heavy  soils  of  fine  texture  and  on  slopes  which  may 
erode  suffer  the  greatest  injury. 

{h)  Injury  to  Reproduction. — A  fire  hot  enough  to  consume 


228  SLASH   DISPOSAL 

the  litter  and  ground  cover  will  kill  small  reproduction  as 
fast  as  it  starts. 

In  unevenaged  stands  the  result  would  ultimately  be  the 
destruction  of  the  forest.  In  certain  evenaged  stands  where 
reproduction  is  not  desired  except  in  the  regeneration  period, 
a  temporary  restriction  of  reproduction  may  be  of  benefit. 
Light  burning  has  been  used  with  satisfactory  results  for  this 
purpose  in  management  under  shelterwood  of  chir  pine  forests 
in  India/"  although  not  without  the  criticism  that  some  other 
agency  than  fire  should  be  employed  for  the  same  purpose.^ 
Such  a  case  is  an  exception  wliich  but  proves  the  rule. 

(c)  Injury  to  Trees  above  Reproduction  Size. —  Surface  fires 
damage  standing  trees  in  ratio  to  their  size  and  inherent 
powers  of  resisting  heat.  Large  trees  and  those  with  thick 
corky  bark  may  escape  injury  while  small  thin  barked  trees 
are  killed.  The  aggregate  amount  of  the  damage  from  even 
a  single  Hght  burn  ^^  is  serious  and  from  repeated  burns  re- 
sults in  heavy  inroads  upon  the  growing  stock. 

{d)  Reduction  in  Density  of  Stocking. — As  a  consequence  of 
the  injuries  to  reproduction  and  growing  stock  the  density 
of  the  stand  is  reduced,  and  the  quahty  and  quantity  of 
production  per  acre  lowered. 

In  conducting  a  light  burning  operation  a  time  is  selected 
when  the  material  is  dry  enough  to  burn  readily,  but  not  so 
dry  as  to  threaten  to  ignite  the  forest  itself,  and  with  climatic 
conditions  favorable  for  controlling  the  fire.  The  advocates 
of  light  burning  minimize  the  damage  done  and  state  that  it 
can  be  avoided  by  raking  the  litter  away  from  the  larger 
trees.  It  is  impracticable  to  do  this  on  a  large  forest  area 
and  to  carry  on  similar  raking  around  the  smaller  trees  and 
reproduction  is  manifestly  out  of  the  question.  If  light 
burning  is  conducted  in  such  a  careful  manner  as  to  save 
reproduction   and   avoid  injury   to   other   standing   trees,  it 


APPLICATION   OF   METHODS 


229 


becomes  an  expensive  method  of  protection  when  repeated 
at  short  intervals. 

With  longleaf  pine  in  the  southern  United  States  it  is  pos- 
sible that  hght  burning  may  be  applicable.  Longleaf  is  so 
fire  resistant,  reproducing  often  in  spite  of  fire,  and  grows  on 
sites  relatively  so  free  from  injury  by  fire  in  a  region  where 
the  total  suppression  of  surface  fires  is  extremely  difficult 
that  it  is  an  open  question  whether  light  burning  cannot  be 
employed  to  advantage. 

/ 

Application  of  Slash  Disposal  Methods  under  Various 
Kinds  of  Cuttings 

Reproduction  Cuttings.  —  Cutting  under  the  '  Clearcutting 
Method.  This  is  one  of  the  few  cuttings  with  which 
broadcast  burning  can  be  employed.  There  are  no  trees 
left  on  the  felling  area  to  be  injured  in  the  fire.  Slash  is 
heavy  after  a  clearcutting,  in  some  cases  lying  several  feet 
deep  over  the  greater  part  of  the  area,  and  consequently 
expensive  to  handle.  Ordinarily  a  clearcutting  method  is 
not  used  unless  the  species  desired  in  the  new  stand  reproduces 
well  on  a  bare  site  free  of  underbrush  and  litter.  Taking  all 
these  effects  into  consideration,  broadcast  burning  frequently 
is  seen  to  be  the  cheapest  and  most  satisfactory  method  of 
slash  disposal.  Conditions  may  be  such  that  it  is  unsafe  to 
burn  broadcast  or  is  not  in  harmony  with  the  silvical  require- 
ments, whereas  a  piling  and  burning  method  might  be  used. 
If  broadcast  burning  is  not  used  a  piUng  method  is  employed. 
Of  the  piling  methods  piling  and  burning  as  the  logging  pro- 
ceeds is  preferable.  Pihng  and  burning  later  would  be  chosen 
only  when  climatic  conditions  made  it  unsafe  to  burn  during 
the  logging  operation. 

Piling  without  burning  is  undesirable  on  a  clearcut  area 
because  so  much  room  is  Hkely  to  be  taken  by  the  piles. 


230  SLASH   DISPOS.\L 

Lopping  of  tops  is  not  suitable  due  to  the  relatively  large 
amount  of  slash  on  the  area. 

Cuttings  under  the  Seed  Tree  Method.  —  The  area  is  left 
quite  bare  with  relatively  few  trees  scattered  singly  or  in 
groups.  There  are  not  enough  of  these  seed  trees  to  make 
impracticable  the  use  of  broadcast  burning.  The  expense 
of  the  operation  will  be  increased  by  the  necessity  of  clearing 
the  slash  away  from  the  seed  trees  and  in  burning  over  the 
area  more  carefully.  Otherwise  what  has  been  said  of  cuttings 
under  the  clearcutting  method  appUes  for  the  seed  tree 
method. 

Cuttings  under  the  Shelterwood  Method.  —  Broadcast  burn- 
ing is  impracticable  as  it  would  result  in  destruction  of  re- 
production and  probably  of  some  of  the  mature  trees  remain- 
ing on  the  area  after  all  but  the  final  cutting.  Piling,  lopping 
or  pulling  tops  are  available.  Where  the  method  is  inten- 
sively apphed  the  slash  may  be  so  small  in  quantity  as  to  re- 
quire no  disposal.  If  the  stand  is  of  open  character  and  the 
site  in  need  of  protection  even  large  tops  may  be  dragged 
away  from  the  standing  trees  and  left  intact.  The  slash  fre- 
quently is  not  too  heavy  to  admit  of  lopping  and  scattering, 
so  as  not  to  interfere  with  reproduction.  This  has  the  ad- 
vantage of  not  requiring  the  use  of  fire,  which  is  apt  to  injure 
reproduction  already  started  and  the  remaining  mature  stand. 

The  lopped  trees  may  form  an  impediment  to  the  start  and 
development  of  reproduction;  in  which  case  piling  and  burning 
either  as  the  logging  proceeds  or  separately  is  advisable.  Care 
is  necessary  to  conduct  the  burning  without  injury  to  repro- 
duction and  mature  trees. 

Cuttings  under  the  Selection  Method.  —  Where  single  tree 
selection  is  used  the  amount  of  slash  in  any  one  place  is  small. 
Lopping  the  tops  without  scattering  fits  the  situation,  par- 
ticularly as  single  tree  selection  is  likely  to  be  used  on  protec- 


APPLICATION  OF   METHODS  23 1 

tion  sites.  In  group  selection  the  trees  so  far  as  possible  are 
felled  in  toward  the  center  of  the  group.  The  tops  can  here 
be  piled  and  burned  without  injury  to  the  forest. 

Since  the  selection  stand  contains  trees  of  all  ages 
in  mixture  the  difficulty  of  burning  slash  without  injury  to 
the  forest  is  greater  than  under  most  other  reproduction 
methods. 

Broadcast  burning  cannot  be  used  without  destroying  the 
unevenaged  forest. 

Cuttings  under  the  Coppice  Methods.- — Utilization  is  nec- 
essarily close  in  order  to  make  possible  the  simple  coppice 
method  of  reproduction.  The  rotation  is  short  and  the  largest 
trees  in  the  stand  when  cut  are  relatively  small.  Only  a 
small  amount  of  slash  consisting  of  small  branches  and  fohage 
is  left  after  the  cutting.  This  material  rots  easily  and  is  not 
abundant  enough  to  smother  sprout  reproduction. 

An  added  reason  for  allowing  the  slash  to  rot  on  the  area 
rather  than  burning  it  up  is  to  prevent  deterioration  of  the 
soil  under  coppice  management. 

The  polewood  coppice  method  provides  for  a  longer  rota- 
tion and  hence  produces  larger  trees  with  bigger  tops.  Even 
so  the  accumulation  of  slash  is  not  enough  to  require  the 
expense  of  piling  and  burning.  In  sprout  stands  of  hardwoods 
the  chief  fire  hazard  comes  from  the  inflammable  leaf  litter 
and  not  from  the  slash.  Surface  fires  serious  enough  to  kill 
mature  trees  can  develop  in  hardwood  leaf  Htter.  Presence 
of  slash  may  increase  the  severity  and  the  difficulty  of  fight- 
ing the  fires,  but  not  sufficiently  to  justify  the  expense  of 
piling  and  burning  the  slash. 

Slash  disposal  after  cuttings  under  the  coppice  with  stand- 
ards method  is  not  advisable  for  the  same  reasons  which  apply 
for  the  simple  and  polewood  coppice  methods. 

Intermediate  Cuttings.  —  The   slash  remaining  after  inter- 


232  SLASH  DISPOSAL 

mediate  cuttings  is  small,  both  in  size  of  pieces  and  in  total 
quantity. 

Intermediate  cuttings  cannot  be  made  without  the  exist- 
ence of  fairly  good  markets;  which  in  turn  permits  of  close 
utiKzation.     Ordinarily  the  slash  does  not  require  disposal. 

In  liberation  cuttings  the  slash  should  be  lopped  and  scat- 
tered wherever  it  is  lying  upon  reproduction. 

Severe  thinnings,  improvement  cuttings,  or  salvage  cuttings, 
particularly  in  coniferous  stands,  may  create  a  slash  heavy 
enough  to  need  disposal.  A  piling  and  burning  method  is 
suggested. 

Severance  cuttings  should  be  followed  by  piling  and  burn- 
ing all  of  the  slash  in  order  to  secure  a  clean  line. 

Selecting  the  Method  of  Slash  Disposal.  —  As  explained 
on  page  216,  the  total  silvicultural  effect  of  slash  disposal  is 
a  composite  of  the  combined  effects  upon  the  soil,  reproduc- 
tion and  upon  the  chief  enemies  of  the  forest,  fires,  insects 
and  fungi.  What  is  best  in  slash  disposal  for  one  of  these 
may  be  injurious  for  another.  In  other  words  in  their  require- 
ments for  treatment  of  slash  to  produce  the  most  satisfactory 
results  these  various  interests  may  conflict. 

From  the  standpoint  of  forest  fires  complete  removal  of 
the  slash,  which  furnishes  a  substantial  part  of  the  fuel  for 
fires,  represents  the  ideal  treatment.  Of  greatest  importance 
is  the  removal  of  the  smaller,  highly  inflammable  portions  of 
the  slash,  while  the  larger  pieces  can  often  be  safely  left.  In 
the  control  of  destructive  insects  the  situation  is  reversed; 
although  as  an  ideal  complete  removal  of  slash  would  be 
desirable,  still  the  part  of  the  slash  of  vital  importance  is  that 
including  the  large  pieces. 

The  greatest  benefit  to  the  soil,  usually  follows  through 
retention  of  all  the  slash;  and  it  is  possible  that  leaving  the 
slash  just  as  it  is  will  be  the  best  method  of  treatment. 


SELECTING  THE   METHOD  233 

In  the  final  choice  of  a  method  for  treating  the  slash  a  com- 
promise must  be  struck  between  conflicting  viewpoints,  in 
such  a  way  as  to  produce  the  most  favorable  total  effect.  In 
arriving  at  this  decision  the  factor  of  cost  and  the  character 
of  other  control  or  remedial  measures,  which  will  be  under- 
taken against  injurious  agencies,  must  be  considered.  Since 
silviculture  aims  at  the  highest  production  not  only  quantita- 
tively, but  financially,  it  follows  that  cost  must  always  be 
kept  in  mind. 

The  cost  of  slash  disposal  may  be  figured  either  on  an  acre- 
age basis  or  by  the  thousand  feet  board  measure  of  timber 
cut.  In  the  final  analysis  the  cost  should  be  expressed  on 
the  acreage  basis.  When  broadcast  burning  is  used  the  total 
cost  per  acre  is  nearly  independent  of  the  amount  of  timber 
cut  per  acre,  while  in  other  methods  of  disposal  the  cost  per 
acre  is  in  proportion  to  the  amount  of  timber  cut.  Since  the 
amount  of  timber  cut  per  acre  varies  from  less  than  one 
thousand  to  over  one  hundred  thousand  feet  board  measure, 
costs  of  slash  disposal  (except  in  the  case  of  broadcast  burn- 
ing) for  comparative  purposes  are  commonly  expressed  on  the 
thousand  board  feet  unit  basis.  This  allows  of  ready  change 
to  per  acre  figures  when  the  amount  cut  per  acre  is  known. 

The  cost  of  slash  disposal  per  thousand  feet  board  measure 
is  greater  for  trees  with  heavy  crowns,  than  for  light  crowned 
trees,  for  small  as  contrasted  with  large  trees,  when  the  cut 
per  acre  is  light  as  compared  with  a  heavy  cut  and  on  rough 
ground  than  on  smooth  ground. 

It  is  evident  that  there  will  be  a  wide  range  in  the  cost  of 
slash  disposal  due  to  the  factors  already  mentioned. 

In  general  the  cost  of  slash  disposal  should  range  from  one 
or  two  cents  to  a  dollar  per  thousand  feet  board  measure  of 
timber  cut.  The  minimum  figures  would  be  attainable  only 
under  the  broadcast  burning  method  with  a  cut  of  fifty  to 


234  -    SLASH  DISPOSAL 

one  hundred  thousand  feet  board  measure  per  acre  or  in 
regions  of  open  forests  not  subject  to  crown  fires.  The  maxi- 
mum of  a  dollar  ought  not  to  be  required,  except  where  in 
small  timber  a  method  of  piling  and  burning  at  different  times 
was  conducted  in  a  most  thorough  manner  or  where  lopping 
with  careful  scattering  was  employed. 

The  average  costs  of  slash  disposal  fall  between  lo  and  50 
cents  per  thousand  feet  board  measure.  Cox  ^^  gives  the 
average  cost  of  slash  disposal  in  the  state  of  Minnesota  as 
10  cents  per  thousand  feet  of  timber  cut.  This  amounts  to 
an  approximate  annual  expenditure  of  $300,000  on  a  basis  of 
three  billion  feet  cut  yearly.  Hirst  ^^  estimated  in  1916  that 
for  the  small  sized  timber  in  the  rough  country  of  northern 
New  England  slash  disposal  would  not  average  less  than  50 
cents  per  thousand  board  feet. 

On  individual  operations  where  costs  go  much  higher,  it  is 
advisable  to  investigate  the  efficiency  of  the  labor  or  to  seek 
other  ways  (either  of  slash  disposal  or  along  entirely  different 
lines)  of  accomphshing  the  desired  silvicultural  result. 

Mason  ^^  suggests  that  in  lodgepole  pine  stands  properly 
regulated  grazing  may  obviate  the  need  of  expenditures  for 
slash  disposal.  Koch  ^^'  ^^  has  favored  extra  patrol  on  cut- 
over  areas  as  a  substitute  for  more  expensive  slash  disposal. 
The  following  quotation  from  the  Report  for  19 19  of  the 
Minnesota  State  Forestry  Board  ^^  is  pertinent. 

"In  some  cases  where  the  timber  still  standing  is  of  excep- 
tional value,  owners  have  been  permitted  to  substitute  three 
years  of  adequate  patrol  for  brush  burning." 

A  present  expenditure  of  several  dollars  per  acre  for  treat- 
ment of  slash  may  be  fully  justified  by  the  saving  of  losses 
which,  if  slash  disposal  were  omitted,  might  be  incurred.  In 
this  connection  Hopping,^  discussing  conditions  in  California, 
says:   "No  matter  what  the  species  of  tree  the  slash  resulted 


REFERENCES  235 

from,  that  slash  breeds  under  ordinary  circumstances  the 
insect  or  insects  destructive  to  standing  timber.  The  annual 
loss  from  this  cause  alone  far  exceeds  any  cost  incurred  from 
the  burning  of  the  slash  at  the  proper  time.  Therefore  the 
consideration  of  the  burning  or  non-burning  of  brush  must 
be  taken  up  from  a  broad  protection  standpoint  and  not  from 
the  standpoint  of  fire  risk  or  cost  alone." 

Similarly,  the  danger  of  fungi  spreading  from  slash  to  living 
timber  may  justify  relatively  large  expenditures  for  special 
treatment  of  the  slash.  The  dangerous  fungi  develop  in  the 
cull  logs  and  other  large  sized  pieces  of  slash,  which  are  not 
disposed  of  in  the  methods  of  slash  disposal  other  than  broad- 
cast burning.  This  latter  method  cannot  always  be  used, 
because  of  the  presence  of  reproduction  and  immature  timber. 
The  special  treatment  ^  necessary  may  take  the  form  either  of: 

(a)  Attempts  to  dry  out  the  slash  and  thus  create  unfav- 
orable conditions  for  the  development  and  fruiting  of  fungi. 
To  accomplish  this  the  cull  logs  and  large  material  of  all  kinds 
must  be  elevated  above  the  ground  and  in  some  cases  be 
stripped  of  bark. 

(b)  Destruction  by  fire  of  the  large  pieces  of  slash.  The 
small  brush  can  be  utilized  for  this  purpose,  so  far  as  it  will  go, 
by  piling  it  on  top  of  and  around  large  material  which  then 
Vv'ill  be  partially  consumed  in  the  burning. 

Both  classes  of  treatment  are  expensive  and  will  increase 
the  cost  of  slash  disposal.  A  combination  of  the  two  is  Hkely 
to  produce  the  most  effective  results. 

REFERENCES 

1.  Hopping,  Ralph.  The  Entomological  Aspect  of  Slash  Disposal.  Pro- 
ceedings of  the  Society  of  American  Foresters,  Vol.  X,  1915,  pp.  183-185. 

2.  Long,  W.  H.  A  New  Aspect  of  Brush  Disposal  in  Arizona  and  New 
Mexico.  Proceedings  of  the  Society  of  American  Foresters,  Vol.  X,  1915,  pp. 
383-398. 


236  SLASH  DISPOSAL 

3.  Long,  W.  H.  Investigations  of  the  Rotting  of  Slash  in  Arkansas. 
Bulletin  496,  United  States  Department  of  Agriculture,  Washington,  1917. 

4.  Hubert,  Ernest  E.  The  Disposal  of  Infected  Slash  on  Timber-Sale 
Areas  in  the  Northwest.     Journal  of  Forestry,  Vol.  XVIII,  1920,  pp.  34-56. 

5.  Mitchell,  J.  A.  Methods  and  Costs  of  Brush  Pihng  and  Brush 
Burning  in  California.  Proceedings  of  the  Society  of  American  Foresters, 
Vol.  VIII,  1913,  pp.  340-353- 

6.  Cox,  Wm.  T.  The  Best  Brush  Burning  Torch.  Forestry  Quarterly, 
Vol.  XI,  1913,  pp.  372-374- 

7.  Stephen,  John  W.  Lopping  Branches  in  Lumbering  Operations. 
Extract  from  the  Fifteenth  Annual  Report,  State  of  New  York  —  Forest,  Fish 
and  Game  Commission,  Albany,  1909,  pp.  94-102. 

8.  Wilson,  Ellwood.  Logging  Debris  an  Imperative  Problem.  Cana- 
dian Forestry  Journal,  Vol.  XIII,  191 7,  p.  1445. 

9.  Chapman,  H.  H.,  with  comments  by  Pearson,  G.  A.  The  Development 
of  a  Brush  Disposal  PoHcy  for  the  Yellow  Pine  Forests  of  the  Southwest. 
Journal  of  Forestry,  Vol.  XVII,  1919,  pp.  693-702. 

10.  Glover,  H.  M.  Departmental  Firing  in  Chir  {Piniis  longifolia)  For- 
ests in  the  Punjab,  Rawalpindi  Division.  The  Indian  Forester,  Vol.  XI, 
Dehra  Dun,  1914,  pp.  292-306. 

11.  Fischer,  C.  E.  C.  The  Need  of  Fire  Protection  in  the  Tropics.  The 
Indian  Forester,  Vol.  38,  Dehra  Dun,  191 2,  pp.  191-221. 

12.  Show,  S.  B.  Light  Burning  at  Castle  Rock.  Proceedings  of  the 
Society  of  American  Foresters,  Vol.  X,  1915,  pp.  426-433. 

13.  Cox,  Wm.  T.  Defending  the  Forest.  The  North  Woods  and  Wild 
Life,  Vol.  6,  19 1 7,  p.  9. 

14.  Hirst,  E.  C.  Biennial  Report  of  the  Forestry  Commission  for  the 
Years  1915-1916,  State  of  New  Hampshire,  Concord,  1916,  pp.  34-35. 

15.  Mason,  D.  T.  Brush  Disposal  in  Lodgepole  Pine  Cuttings.  Pro- 
ceedings of  the  Society  of  American  Foresters,  Vol.  X,  1915,  pp.  399-404. 

16.  Koch,  Elers.  The  Economic  Aspect  of  Slash  Disposal.  Proceedings 
of  the  Society  of  American  Foresters,  Vol.  IX,  1914,  pp.  356-359. 

17.  Koch,  Elers.  Some  Suggestions  on  Brush  Disposal.  Forestry  Quar- 
terly, Vol.  XI,  1913,  pp.  519-526. 

18.  Minnesota  State  Forestry  Board,  Annual  Report  to  the  Governor  for 
the  Year  1919,  p.  10. 

Munger,  T.  T.     Western  Yellow  Pine  in  Oregon.     Bulletin  418,  United  States 
Department  of  Agriculture,  Washington,  191 7,  pp.  47-48. 


CHAPTER  XIV 

FOREST  PROTECTION 

General  Considerations.  —  It  has  been  indicated  (see  page 
6)  that  one  part  of  silviculture  deals  with  protection  of  the 
forest  against  various  injurious  agencies.  These  agencies  are 
so  numerous  and  many  are  so  destructive  that  the  production 
of  profitable  tree  crops  is  impossible  unless  adequate  protec- 
tion be  afforded. 

It  is  necessary  that  the  silviculturist  be  continually  on  the 
watch  for  evidence  of  the  presence  and  activity  of  injurious 
agencies.  The  character  of  the  damage  caused  by  and  the 
appearance  and  characteristics  of  the  injurious  agencies  likely 
to  be  operating  in  a  given  forest  must  be  understood.  Each 
locaUty  will  have  problems  of  protection  pecuHar  to  itself  but 
the  same  broad  types  of  enemies  are  of  general  occurrence. 

A  most  systematic  presentation  of  the  agencies  against 
which  forest  protection  must  be  effected  is  that  contained  in 
Schhch's  ^  Manual  of  Forestry,  Vol.  IV,  which  is  an  English 
adaptation  of  Der  Forstschutz  by  Hess.^ 

The  main  headings  and  subdivisions  from  Schlich's  Manual 
of  Forestry,  Vol.  IV,  are  herewith  given  to  indicate  the  scope  of 
forest  protection. 

Forest  Protection^ 
Part  I.     Protection  of  forests  against  man. 
Forest  boundaries. 
Protection  of  forests  against  irregularities 

in  utilizing  forest  produce. 
Protection  of  the  forest  against  offences. 
Protection  against  forest  rights. 
237 


238  FOREST  PROTECTION 

Part  II.     Protection  of  the  forest  against  animals. 
Protection  against  game. 
Protection  against  other  rodents. 
Protection  against  birds. 
Forest  insects. 

Insects  useful  to  forests. 

Injurious  forest  insects. 

Part  III.     Protection  against  plants. 

Protection  against  forest  weeds. 
Protection  against  fungi. 

Part  IV.     Protection  against  atmospheric  influences. 

These  include  frost,  insolation,  wind, 
violent  rain,  hail,  snow  and  rime. 

Part  V.     Protection  against  non-atmospheric  natural 
phenomena. 
Protection  against  damage  by  water. 
Protection  against  avalanches. 
Protection  against  shifting  sand. 
Protection  against  forest  fires. 

Part  VI.     Protection  against  certain  diseases. 

These  include  red-rot,  white-rot,  stag- 
headedness,  abnormal  needle-shedding 
and  damage  from  acid  fumes. 

Protection  from  grazing  animals  (domestic)  is  curiously 
enough  not  placed  in  "Part  II,  Protection  of  the  forest  against 
animals,"  but  under  "Part  I,  Protection  of  forests  against 
man,"  under  the  subdivision  "Protection  of  forest  against 
irregularities  in  utiHzing  forest  produce." 

The  relative  importance  of  a  given  branch  of  protection 
changes  from  region  to  region.     This  is  illustrated  by  the 


GENERAL   CONSIDERATIONS  239 

space  in  Schlich's  Manual,  Vol.  IV,  devoted  to  the  considera- 
tion of  forest  fires.  Out  of  approximately  600  total  pages 
less  than  20  pages  are  occupied  by  fire  protection.  In  America 
this  line  of  protection  at  the  present  time  receives  primary 
consideration.  While  the  emphasis  placed  on  the  various 
branches  of  protection  will  shift  from  country  to  country,  yet 
it  is  true  that  the  same  kind  of  injurious  agencies  described 
by  Fisher  ^  and  Hess  are  to  be  encountered  in  America.  Much 
can  be  learned  from  these  two  standard  works. 

The  four  most  important  agencies  against  which  forest 
protection  is  required  in  America  are: 

Fires 

Insects 

Fungi 

Grazing  animals  (domestic). 

Forest  protection  in  its  appUcation  to  the  control  of  injurious 
agencies  and  the  prevention  of  losses  is  a  highly  specialized 
subject  (or  group  of  subjects).  The  classification  and  de- 
scription of  injurious  agencies,  the  scientific  facts  which  must 
be  known  in  determining  control  methods  and  the  adminis- 
trative problems  connected  with  control  and  prevention  of 
losses  call  for  the  development  of  speciaHsts  in  several  of  the 
more  important  branches  of  forest  protection. 

It  is  impossible  (and  out  of  place)  within  the  limits  of  a 
work  on  general  silviculture  to  treat  fully  of  forest  pro- 
tection. 

All  that  can  be  attempted  here  is  to  select  the  more  de- 
structive injurious  agencies  and  to  present  (in  the  succeeding 
chapters)  for  each  the  following  information: 

(a)  Description  of  the  damage  caused. 
{b)'  Character  of  the  injurious  agency. 


240  FOREST  PROTECTION 

(c)  Condensed  statement  of  the  methods  of  protection, 
with  particular  reference  as  to  how  and  to  what 
extent  cuttings  and  special  silvicultural  treatment 
of  the  stand  can  be  utiUzed  to  assist  control  and 
prevention  of  loss. 


REFERENCES 

1.  Fisher,  W.  R.     Forest  Protection.     Schlich's  Manual  of  Forestry,  Vol. 
IV,  London, 1895. 

2.  Hess,  Richard.     Der  Forstschutz.     3rd  edition.    Leipzig,  1896-1900. 

FuRST,  Hermann,  translated  by  John  Nisbet.  The  Protection  of  Woodlands 
against  Dangers  arising  from  Organic  and  Inorganic  Causes.  Edinburgh, 
1893. 

LovEjOY,  P.  S.  Forest  Biology.  Journal  of  Forestry,  Vol.  XV,  191 7,  pp. 
203-214. 


CHAPTER  XV 
PROTECTION  AGAINST  FOREST  FIRES 

Effects  of  Forest  Fires.  —  Forest  fires  are  in  the  main  in- 
jurious to  forest  production.  In  certain  instances,  beneficial 
results  may  accrue.  There  exists  such  a  wide  disparity  be- 
tween the  relative  importance  of  the  injurious  and  beneficial 
influences  that  the  latter  have  often  been  overlooked.  In 
this  chapter  the  effects  of  fires  are  assumed  to  be  injurious 
unless  otherwise  specifically  stated. 

Annual  Fire  Loss.  —  A  general  statement  covering  the  total 
damage  done  by  forest  fires  in  the  average  season  or  in  any 
one  year  for  a  territory  as  large  as  the  United  States  must  be 
a  mere  approximation  owing  to  lack  of  statistics  for  many 
portions  of  the  country  and  to  incomplete  estimation  of  the 
damage.  Plmnmer  ^  makes  the  statement  that  "Forest  fires 
in  the  United  States  have  caused  an  average  annual  loss  of 
about  seventy  human  fives,  the  destruction  of  trees  worth  at 
the  very  least  $25,000,000  and  the  loss  of  stock,  crops,  build- 
ings and  other  improvements  to  the  amount  of  many  milUons 
more.  To  these  must  be  added  enormous  losses  from  the 
destruction  of  young  tree  growth,  deterioration  of  the  soil, 
damage  to  water-courses  and  adjacent  property  by  low  water 
and  flood,  interruption  of  business,  and  depreciation  of 
property." 

This  estimate,  pubHshed  in  191 2,  was  based  on  a  careful 

search  of  all  the  sources  of  information.     It  may  be  taken  as 

representative  of  the  period  in  the  United  States  before  the 

awakening  of  pubfic  interest  and  the  development  of  scien- 

241 


242  FOREST   PROTECTION 

tific  methods  of  fire  protection,  which  began  after  the  fire 
season  of  1910.  The  last  statistics  issued  by  the  United 
States  Department  of  Agriculture^  were  for  1915  and  gave 
the  loss  for  that  year  in  timber  and  improvements  alone  as 
$7,000,000  with  40,000  fires  and  6,000,000  acres  burned  over, 
or  I.I  per  cent  of  the  total  forest  area  of  the  country.  191 5, 
however,  was  a  favorable  year  with  relatively  few  serious  fires. 
An  excellent  example  of  what  has  been  accomplished  since 
fire  protection  was  begun  in  the  way  of  reducing  the  annual 
loss  is  furnished  by  the  Oregon  State  Board  of  Forestry.^ 
Since  1907,  records  covering  the  state  of  Oregon  have  been 
kept  with  the  following  results: 

A  period  without  good  protection  1908,  09,   10,  average 

annual  fire  loss $663,935 

A  period  with  well  organized  protective  system,  1911-16, 

average  annual  fire  loss 16,250 

To  this  was  added  during  1911-16  an  average  annual  charge 
$119,245  for  costs  of  fire  protection. 

The  costs  of  protection  plus  the  loss  are  far  below  the  loss 
alone  before  an  efficient  protection  system  was  installed. 
Many  similar  examples  can  be  drawn  from  the  records  of 
other  organizations. 

The  losses  from  fires  (other  than  forest  fires)  during  the 
last  30  years  rose  from  $102,940,000  *  in  1888  to  $242,302,000 
in  191 7.  1906  with  $450,751,000  has  the  highest  loss  for  any 
one  year,  while  1897  with  $101,265,500  is  the  lowest  year. 
The  annual  average  loss  for  the  first  five  years  of  this  period 
was  $120,534,000  as  compared  with  $201,701,000  for  the  last 
five-year  period.  This  is  an  increase  of  67  per  cent.  During 
the  same  period  great  improvements  in  fire  prevention  and 
control  were  introduced  and  the  sums  spent  for  the  purpose 
increased. 

*  These  figures  are  based  on  reports  compiled  by  the  Standard  Pubhshing 
Company,  Boston,  Mass.,  and  furnished  by  J.  H.  Kelsey,  statistician. 


INJURIES   CAUSED   BY   FOREST  FIRES  243 

While  the  increase  of  losses  in  conjunction  with  rise  in 
expense  for  protection  may  appear  discouraging,  such  is  not 
the  case. 

The  enormous  increase  in  the  number  of  buildings  and 
greater  concentration  of  values,  due,  for  example,  to  more 
expensive  buildings,  and  to  larger  stocks  of  goods  carried  by 
business  firms,  would  account  for  a  larger  number  of  fires  and 
for  higher  losses. 

The  wealth  of  the  country  has  risen  far  more  rapidly  than 
have  losses  from  fires.  Hence  the  percentage  of  loss  to  total 
value  has  fallen. 

Similar  results  may  be  anticipated  (and  already  are  being 
received  in  many  forest  regions)  when  forest  property  is 
protected  from  fire.  Whether  the  actual  amount  of  damage 
will  increase  annually  as  the  value  of  forest  property  rises 
remains  to  be  seen.  Past  statistics  of  damage  are  based  on 
a  period  when  virtually  no  protection  was  afforded  forest 
property.  The  estabHshment  of  a  protective  system  may  be 
expected  to  have  the  immediate  effect  of  reducing  the  losses 
below  figures  for  the  no  protection  period,  although  the  latter 
are  incomplete  and  too  low.  After  the  protection  system  is 
well  estabhshed,  it  may  be  that  as  forest  property  values  rise 
forest  fire  losses  also  will  go  up  in  amount,  though  falHng  in 
per  cent  of  total  protected  value  due  to  higher  efficiency  in 
protection. 

Classification  of  the  Injuries  Caused  by  Forest  Fires.  — 
The  injury  caused  by  forest  fires  may  be  classified  under 
eight  heads,  of  which  the  first  four  have  a  direct  relation  to 
the  results  of  apphed  silviculture  attained  in  any  forest. 

1 .  Injury  to  trees  containing  merchantable  material. 

2.  Injury  to  young  growth  including  reproduction. 

3.  Injury  to  the  soil. 


244  FOREST  PROTECTION 

4.  Injury  to  the  productive  power  of  the  forest. 

5.  Injury  to  forage. 

6.  Injury  to  stream  flow  and  industry. 

7.  Injury  to  other  property.  , 

8.  Injury  to  human  life.  ' 

Injury  to  Trees  Containing  Merchantable  Material.  —  The 
damage  may  range  from  slight  fire  scars  at  the  base  to  'com- 
plete consumption  of  the  tree.  The  latter  occurs  rarely  even 
in  exceptionally  severe  fires.  Frequently  large  trees  are  killed 
outright.  Death  is  caused  by  the  killing  of  the  cambium  or 
living  layer  between  the  bark  and  the  wood.  A  temperature 
of  54°  C.^  (129.2°  F.),  is  sufficient  to  kill  the  cambium.  If 
the  cambium  is  killed  all  the  way  round,  the  tree  is  girdled 
and  dies.  Dead  cambium  can  usually  be  told  by  its  dark 
color  in  contrast  to  its  light  shade  when  in  normal  condition. 
It  is  not  necessary  that  the  bark  be  burned  off  to  cause  death 
of  the  tree.  Heat  wliich  only  scorches  the  outer  bark  is  often 
sufficient  to  kill  the  cambium. 

During  the  early  part  of  the  growing  season  when  cell 
division  in  the  cambium  layer  is  at  its  height  the  cambium  is 
more  sensitive  to  heat  than  later  on  in  the  summer  or  during 
the  dormant  period.^ 

Power  of  resistance  to  fire  differs  for  each  species  of  tree. 
These  differences  between  species  are  due  primarily  to  the 
character  and  thickness  of  bark.  Layers  of  cork,  which  act 
as  non-conductors  of  heat,  are  developed  to  a  greater  or  less 
extent  in  the  bark.  A  tree  which  develops  thick  corky  bark 
is  better  protected  than  one  with  thinner  and  less  corky 
covering.  Tree  bark  may  be  soft,  flaky,  easily  inflammable 
and  apt  to  burn  through  to  the  wood  underneath,  or  it  may 
be  hard,  ignited  with  difficulty  and  rarely  burned  through. 

Old  trees  of  any  given  species  are  better  protected  against 


INJURY   CAUSED   BY  FOREST  FIRES  245 

fire  than  the  young  trees  because  with  age  the  bark  tliickens 
and  tends  to  become  more  corky.  Trees  which  secrete  resin  in 
the  bark  or  exude  pitch  as  a  result  of  insect  attacks  are  easily 
injured.  Where  the  pitch  is  plentiful  a  fire  may  run  up  the 
tree  kilHng  the  cambium  on  one  side  for  many  feet  above  the 
ground  and  leaving  a  long  scar  called  a  cat's  face. 

Conifers  suffer  more  severely  from  fire  than  hardwoods. 

When  heat  from  a  fire  reaches  the  roots  of  trees  severe 
injury  or  death  results.  This  is  the  case  because  tree  roots  are 
less  thoroughly  protected  by  tliick  bark  than  the  portions  above 
ground,  and  probably  are  more  sensitive  to  heat.  Trees  with 
shallow  root  systems  suffer  more  than  the  deep-rooted  species. 

Old  trees  can  be  found  all  hollowed  out  at  the  base  by  fires. 
In  some  cases  spaces  big  enough  to  admit  one  or  more  men 
have  been  burned  out.  Such  hollows  are  rarely  if  ever  the 
work  of  one  fire  but  represent  the  effects  of  several  fires. 
Once  the  bark  has  been  burned  away  on  one  side  succeeding 
fires  burn  more  readily  in  the  exposed  wood. 

Where  trees  containing  merchantable  material  are  killed 
outright  they  should  be  cut  and  utihzed  before  the  timber 
decays  or  is  attacked  by  insects.  This  is  not  always  possible 
if  the  trees  are  few  in  number,  scattered  or  located  in  inac- 
cessible places.  Frequently  fire  killed  timber  can  be  sal- 
vaged for  a  large  percentage  of  its  value  before  the  fire. 
Burned  timber  in  some  cases  is  valueless  a  year  after  the  fire, 
in  other  cases  remains  sound  for  several  years.  Climatic 
conditions,  the  species,  and  the  question  of  whether  the  bark 
falls  from  the  trunk  soon  after  the  fire  are  the  main  factors 
influencing  the  length  of  time  during  which  fire  killed  timber 
remains  sound. 

In  a  dry  climate  with  a  species  relatively  free  from  insects 
and  fungi  and  under  circumstances  causing  the  tree  to  shed 
its  bark  deterioration  is  delayed. 


246  FOREST  PROTECTION 

In  one  case  which  came  to  the  writer's  attention  large  white 
pines  {Pinus  Strohus)  growing  in  Nehasane  Park  in  the  western 
Adirondacks  and  killed  by  a  fire  in  1903,  were  utiHzed  12  to 
14  years  after  the  fire.  Although  riddled  with  worm  holes 
90  per  cent  of  the  timber  was  sound  enough  for  building 
purposes  where  appearance  was  not  an  essential.  The  timber 
was  old  growth  and  hence  was  nearly  all  heart-wood  which 
fact  had  much  to  do  with  its  lasting  qualities. 

Where  merchantable  trees  are  injured  but  not  killed  by  fire 
it  may  be  advisable  to  cut  them.  Small  fire  scars  exposing 
the  wood  offer  advantageous  points  of  attack  for  fungi  and 
insects.^  Extensive  burns  in  the  base  of  a  tree  weaken  it  and 
may  result  in  breakage  by  wind.  Whether  it  is  safe  to  leave 
an  injured  tree  and  for  how  long  a  time  cannot  be  determined 
without  a  knowledge  of  the  species,  particularly  its  insect 
and  fungous  enemies. 

The  final  loss  (chargeable  to  fire)  of  merchantable  material 
in  fire  scarred  trees  through  breakage  by  wind,  decay  and 
insects  frequently  exceeds  the  value  of  the  timber  consumed 
or  directly  killed  by  the  fire. 

Injury  to  Young  Growth  including  Reproduction.  —  Trees 
under  merchantable  size  and  reproduction,  with  thinner  bark 
and  crowns  near  the  ground,  are  more  easily  killed  and  con- 
sumed by  fire  than  trees  of  merchantable  size. 

Fire  acts  in  the  same  way  on  small  trees  as  on  large  ones 
but  inflicts  relatively  greater  injuries  on  the  former. 

Even  where  small  trees  are  only  partially  girdled  by  a  fire 
their  potential  value  is  greatly  reduced .  Many  years  must  elapse 
before  the  trees  are  merchantable.  During  this  time  insects 
and  fungi  have  abundant  opportunity  to  enter  through  the  fire 
scars  or  elsewhere  as  a  consequence  of  the  weakened  condition 
of  the  trees  and  frequently  render  them  worthless  or  of  poor 
quality  by  the  time  merchantable  dimensions  are  attained. 


INJURY   CAUSED   BY  FOREST  FIRES  247 

Injury  to  the  Soil.  —  Forest  fires  in  their  action  on  the  soil 
affect  its  physical  rather  than  its  chemical  properties.  Min- 
eral soil  itself  is  rarely  changed  chemically  by  the  action  of 
forest  fires. 

Its  physical  properties  may  be  radically  altered.  From  the 
standpoint  of  tree  growth  the  physical  properties  of  the  soil 
are  recognized  to  be  of  more  importance  than  the  chemical. 
Physical  properties  of  soils  are  influenced  by  fires  through 
decrease  in  the  humus  content.  Humus  is  in  fact  the  key  to 
good  physical  condition  of  the  soil. 

A  severe  fire  which  kills  most  of  the  trees  opens  the  forest 
canopy,  burns  off  the  litter  and  exposes  the  soil  to  the  drying 
influences  of  sun  and  wind.  The  humus  in  the  soil  disappears 
and  without  Htter  or  trees  to  furnish  litter  no  more  humus  is 
formed.  The  soil  on  bare  burned  areas  consequently  dete- 
riorates in  physical  condition.^ 

Heavy  soils  become  dry,  hard,  impervious  to  water  and 
often  crack  open.  Sandy  soils  become  hotter,  more  porous 
and  leachy.  The  mineral  salts  left  in  the  wood-ashes  are 
apt  to  be  blown  or  washed  off  the  surface  or  leached  away 
through  the  soil. 

A  fire  of  the  Hghtest  type  which  consumes  the  Htter  but 
does  not  directly  injure  the  standing  trees  causes  little  or  no 
injury  to  the  soil.  The  loss  of  the  accumulated  Htter  does 
not  prove  serious  provided  a  forest  canopy  exists  to  provide 
more  without  delay.  Light  fires  burning  over  the  same 
ground  every  year  consume  the  annual  leaf-fall  and  thus  keep 
the  ground  bare  of  Htter.  Under  these  circumstances,  when 
the  humus  in  the  soil  is  once  exhausted  the  soil  deteriorates. 
Hence  repeated  Hght  fires  seriously  injure  the  soil. 

In  some  places  forests  are  growing  with  boulders  or  soHd 
ledges  of  rock  only  a  few  inches  below  the  surface.  Here  the 
soil  consists  largely  of  organic  material  and  may  be  completely 


fttOPEnry  imnARY 

IL  C  State  CJkgt 

248  FOREST  PROTECTION 

consumed  by  a  severe  fire.  The  bare  rock  may  be  left  ex- 
posed and  in  such  a  case  the  soil  has  been  entirely  destroyed. 

A  soil  lacking  humus  and  bare  of  litter  is  subject  to  erosion. 
This  carries  away  the  most  fertile  portion  of  the  soil.  In 
extreme  cases  the  entire  surface  layers  of  soil  may  be  eroded 
leaving  exposed  the  subsoil  or  even  the  underl}dng  rock. 

Injury  to  the  Productive  Power  of  the  Forest.  —  Loss  may  be 
sustained  either  in  reduced  quantity  or  quahty  of  production. 
This  is  primarily  dependent  on  the  condition  of  the  soil,  and 
the  extent  to  which  the  individual  trees  have  been  damaged. 

Fire  injury  to  the  productive  power  of  the  forest  may  be 
classified  as  follows: 

(a)  Injury  due  to  replacement  of  good  by  poor  species  or  to 
failure  of  the  burned  areas  to  restock. 

Frequently  the  natural  reproduction  following  a  fire  is  of 
species  inferior  to  those  previously  occupying  the  ground.  In 
some  cases  this  situation  is  reversed  and  a  more  valuable 
species,  preferring  an  open  burned-over  seedbed,  seizes  the 
opportunity  to  restock  the  burn.  This  is  an  example  of  the 
beneficial  influence  of  fire. 

In  numerous  instances  no  natural  reproduction  follows  the 
fire  and  the  burn  becomes  barren. 

(6)  Injury  due  to  reduction  in  the  density  of  stocking. 

Fires  which  do  not  destroy  the  whole  stand  may  break  the 
canopy  and  have  the  general  effect  of  making  the  stand  more 
open  by  reducing  the  number  of  trees  below  the  density 
required  for  highest  production. 

(c)  Injury  due  to  the  poor  growth  of  individual  trees. 

Trees  partially  girdled  at  the  base  have  lost  part  of  their 
equipment  for  transporting  food  materials  and  for  building 
wood  structure.  This  throws  an  added  burden  on  the  cam- 
bium layer  of  the  ungirdled  portions.  Increased  growth  may 
take  place  here,  as  a  result  of  the  enlarged  food    supplies 


INJURY   CAUSED   BY  FOREST  FIRES  249 

which  pass  through,  or  in  response  to  the  greater  mechanical 
strains  following  the  injury.  Except  on  cross  sections  through 
the  burned  part  of  the  tree  the  growth  will  show  a  decrease. 
Analyses  of  fire  injured  trees  made  several  years  after  the 
fire  show,  as  contrasted  to  growth  before  the  fire,  increases 
in  rate  of  growth  on  the  stump  section  and  reduction  on 
sections  above  the  wounds. 

(d)  Injury  due  to  forced  cutting  of  merchantable  material 
before  financial  maturity. 

Where  trees  without  present  merchantable  value  are  killed 
it  is  quite  evident  that  a  sacrifice  is  involved  which  may  be 
estimated  on  the  basis  of  the  future  value  of  the  stand  dis- 
counted to  the  present  time.  Equally  true  is  it  that  the  loss 
in  the  case  of  fire  killed  trees  of  merchantable  size  is  not  alone 
the  reduction  in  present  value  but  should  include  the  sum 
lost  by  not  allowing  these  trees  to  grow  longer  and  be  har- 
vested at  the  time  of  their  financial  maturity. 

Injury  to  Forage.  —  Fires  burn  readily  in  dry  grass  and 
other  plants  of  forage  value.  In  some  cases  fire  may  be  of 
temporary  value  in  burning  off  a  mat  of  dry  dead  vegetation 
and  enabling  stock  to  get  at  the  tender  green  shoots  beneath. 
In  the  final  analysis  fire  tends  to  kill  the  roots  of  the  plants, 
thus  reducing  the  density  of  stocking,  and  to  replace  good 
species  by  those  of  inferior  value  for  forage.^  Serious  damage 
to  forage  can  be  prevented  by  grazing  so  regulated  that  masses 
of  dry  and  inflammable  forage  do  not  accumulate. 

Inflammable  forage  is  in  some  forests  the  principal  fuel  for 
the  rapid  spread  of  fires.  If  this  forage  is  used  by  stock  while 
green  the  fire  danger  is  reduced. 

Injury  to  Stream  Flow  and  Industry.  —  Under  "Injury  to 
SoiV  erosion  was  shown  to  be  a  consequence  of  forest  fires. 
Damage  from  erosion  is  felt  not  only  on  the  lands  eroded  but 
m  the  lower  course  of  the    stream   down  which  the  eroded 


250  FOREST   PROTECTION 

material  is  transported.  River  channels  and  reservoirs  are 
filled  with  detritus  and  deposits  of  rock  and  soil  are  left  on 
lands  near  the  stream.  Where  the  soil  deposited  is  of  fine 
texture  and  fertile  the  lands  covered  may  be  benefited.  The 
harmful  effects  of  erosion  far  outweigh  any  such  advantage. 

A  bare  soil  prevents  the  forest  from  performing  its  function 
as  a  regulator  of  stream  flow.  Lacking  the  sponge-like  cover 
of  Utter  and  humus  a  bare  soil  causes  rapid  surface  run-off  of 
water  instead  of  absorbing  it  and  feeding  it  out  slowly  from 
springs.  Floods  with  their  attendant  damage  are  thus 
caused  and  low  and  high  water  stages  made  more  pronounced. 

This  fluctuation  in  water  level  together  with  the  eroded 
material  in  the  channel  interferes  with  navigation,  and  often 
necessitates  expensive  dredging  operations.  Power  plants 
and  factories  relying  on  water  power  require  a  continuous  and 
uniform  supply  of  water  rather  than  one  which  fluctuates 
widely  in  volume. 

Smoke  from  forest  fires  has  interfered  with  industry  and 
caused  extra  expense  by  producing  dark  days  and  dry  fogs.^ 

Injury  to  Other  Property.  —  Buildings,  five  stock,  and  prop- 
erty of  all  kinds  are  at  times  threatened  by  forest  fires  and 
serious  losses  result.  The  principal  loss  is  to  property  found 
within  the  forest  or  in  small  clearings  surrounded  by  woods. 
Whole  towns  have  been  wiped  out  by  forest  fires. 

Injury  to  Human  Life.  —  Rarely  if  ever  in  the  United  States 
does  a  year  pass  without  loss  of  human  fife  as  a  direct  conse- 
quence of  forest  fires.  The  greatest  loss  of  life  on  record  in 
any  one  fire  took  place  in  the  Peshtigo  fire  of  October,  187 1, 
in  Wisconsin.     Fifteen  hundred  persons  perished  in  this  fire.^ 

Character  of  Forest  Fires.  —  Forest  fires  are  divided  into 
three  classes:    ground,  surface  and  crown  fires. 

Ground  fires  occur  only  where  thick  accumulations  of 
humus  or  duff  are  found  and  burn  in  this  layer  of  organic 


INJURY   CAUSED   BY  FOREST  FIRES  251 

material.  On  account  of  the  depth  of  the  humus  (often  one 
to  over  two  feet  in  thickness)  ground  fires  apparently  burn 
underground  in  the  soil  itself.  Actually  only  the  vegetable 
matter  is  consumed  and  the  fire  is  burning  above  the  soil  or 
in  pockets  formed  by  decaying  roots.  Such  fires  are  sometimes 
termed  "  duff  "  fires.^ 

When  the  surface  is  wet  by  a  Hght  shower,  but  the  duff 
beneath  is  dry,  a  ground  fire  may  burn  the  lower  layer  of 
organic  material,  leaving  the  surface  intact  supported  by  a 
network  of  plant  roots.  When  the  fire  is  burning  under- 
ground, in  this  way,  its  exact  location  is  difficult  to  deter- 
mine. Cases  are  on  record  where  ground  fires  burned  for 
several  months  in  swamps.  Such  fires  are  said  to  have  lasted 
through  an  entire  winter  under  a  blanket  of  snow. 

The  feeding  roots  of  the  trees  extend  throughout  the  thick 
humus  layer  and  are  easily  killed  by  the  ground  fire.  Such  a 
fire  ordinarily  kills  all  the  trees  on  the  area  burned  over. 

Deep  deposits  of  humus  are  formed  only  under  conditions 
which  retard  its  normal  decomposition.  In  swamps  and  low- 
lands, with  excess  of  water,  the  organic  matter  does  not 
readily  decay.  At  high  altitudes  and  in  northern  latitudes,  on 
account  of  the  cold  damp  cHmate  even  upland  sites  may 
develop  thick  beds  of  duff.  This  is  particularly  the  case  with 
coniferous  stands. 

Ground  fires  are  relatively  rare  as  compared  with  other  kinds 
of  fires  because  the  material  on  which  they  feed  does  not 
dry  out  except  in  seasons  of  drought,  and  sites  on  which  they 
may  occur  form  a  small  percentage  of  the  total  forest  area. 

Surface  fires  are  those  which  burn  on  or  near  the  ground  in 
the  humus,  fitter,  ground  cover  and  underbrush.  They  are 
the  commonest  kind  of  fire  and  occur  in  all  parts  of  the 
country. 

Crown  fires  burn  in  the  crowns  of  the  trees.     In  tall  timber 


252  FOREST  PROTECTION 

the  main  fire  may  be  one  to  two  hundred  feet  above  the  ground. 
They  are  restricted  ahnost  entirely  to  coniferous  forests  which 
have  inflammable  foHage  and  retain  it  throughout  the  year; 
although  there  are  certain  species  of  broadleaved  shrubs  and 
dwarf  trees  with  evergreen  foliage  of  an  inflammable  char- 
acter upon  which  crown  fires  might  feed.  In  the  case  of 
broadleaved  species  the  foliage,  while  on  the  trees,  remains 
green  and  does  not  occur  in  such  close  arrangement  as  in  the 
case  of  conifers.  One  instance  is  known  where  a  crown  fire 
ran  through  a  stand  of  oak  and  chestnut-.  The  fire  occurred 
in  the  fall  and  the  chestnut  trees  due  to  injuries  by  chestnut 
blight  retained  the  dry  chestnut  burrs  and  much  of  the 
foliage.  The  foliage  of  the  oak  also  had  shriveled  up  and 
remained  on  the  trees.  This  combination  furnished  enough 
inflammable  material  for  the  crown  fire. 

Crown  fires  apply  heat  to  the  tender  twigs  throughout  the 
top  and  usually  are  fatal  to  the  trees  affected. 

A  crown  fire  is  accompanied  by  a  surface  fire.  In  fact  the 
burning  material  on  the  ground  greatly  assists  in  creating  a 
steady  volume  of  heat  and  enables  the  fire  to  progress,  as  a 
crown  fire,  over  places  where  without  this  assistance  it  would 
stop.  Advantage  is  taken  of  this  fact  in  fighting  crown  fires 
by  burning  off  the  inflammable  surface  material  ahead  of  the 
crown  fire. 

Fires  ordinarily  start  as  surface  fires.  Then  where  deep 
deposits  of  humus  are  reached  a  ground  fire  develops. 

Crown  fires  sometimes  originate  as  a  result  of  Hghtning 
striking  some  tall  dry  stub  and  setting  it  afire,  or  more  com- 
monly start  from  a  surface  fire.  Dry  moss  hanging  from  the 
trunk  or  branches,  inflanmiable  pitch  on  the  bark,  the  burning 
tops  of  a  mass  of  reproduction,  or  even  the  flames  from  a  hot 
grass  fire  may  serve  to  carry  the  fire  upward  and  ignite  the 
crowns. 


INJURY   CAUSED   BY  FOREST  FIRES  253 

At  first  a  surface  fire  burns  out  from  its  starting  point  in 
circular  form,  and  would  so  continue  were  it  not  for  various 
factors  which  at  once  begin  to  control  its  development.  The 
wind  is  of  primary  importance  and  soon  gives  the  fire  an 
elliptical  shape,  the  leeward  side  progressing  most  rapidly 
while  the  windward  side  burns  slowly  or  dies  out. 

Crown  fires  advance  only  in  the  direction  of  the  wind. 
Burning  brands  and  embers  are  carried  forward  by  the  wind 
and  set  other  fires  in  advance  of  the  original  one.  Thus 
several  fires  both  surface  and  crown  are  apt  to  be  burning 
and  may  combine.  Carried  by  the  wind  a  crown  fire  may 
leap  a  quarter  of  a  mile  or  more  from  one  side  of  a  valley,  to 
the  other,  sometimes  leaving  unburned  the  timber  in  the 
center. 

Ground  fires  progress  slowly,  not  being  affected  by  the 
wind,  with  rather  uniform  destructiveness  and  consume  all 
the  inflammable  material  in  their  path.  Such  a  fire  may 
burn  over  several  acres  in  a  day  or  may  cover  only  a  fraction 
of  an  acre. 

Surface  fires  range  from  a  slow  advance  in  a  forward  direc- 
tion of  less  than  a  mile  per  day  to  an  average  of  several  miles 
per  day  and  in  the  case  of  some  grass  and  brush  fires  may  attain 
a  speed  of  several  miles  per  hour. 

Crown  fires  progress  with  great  rapidity,  in  fact  speed  is 
essential  for  the  existence  of  a  crown  fire.  It  is  more  difl&cult 
to'secure  definite  figures  for  the  spread  of  such  fires  as  con- 
trasted to  the  other  two  classes.  Graves  ^  states  that  six  to 
seven  miles  per  hour  is  probably  a  maximum  rate. 

In  the  past  the  most  severe  fires  have  occurred  in  the 
northern  part  of  the  United  States  above  the  43rd  parallel  of 
latitude  in  three  districts:  (i)  New  York  and  the  New 
England  States,  (2)  the  Lake  States  and  (3)  the  Pacific 
northwest  including  Western  Montana,  Idaho,  Washington 


254 


FOREST   PROTECTION 


and  Oregon.  Climate  and  forest  conditions  are  responsible 
for  this  grouping.  Throughout  the  southern  half  of  the  coun- 
try, fires,  while  prevalent,  are  of  a  less  severe  character. 

To  bring  out  the  location  and  extent  of  large  fires  in  the 
past  a  map  prepared  by  the  United  States  Forest  Service,^ 
showing  historic  fires,  is  reproduced.     (See  Fig  82.) 


Fig.  82. 

Map  showing  the  location  of  the  principal  historic  forest  fires  which  have 
occurred  in  the  United  States  since  the  year  1800.  Copied  from  "Forest 
Fires,"  by  F.  G.  Plummer,  Bulletin  117,  Forest  Service,  United  States  De- 
partment of  Agriculture,  page  22. 


Factors  Influencing  the  Spread  and  Severity  of  Forest 
Fires.  —  All  silvicultural  operations  should  so  far  as  practi- 
cable be  conducted  in  a  manner  that  will  minimize  the  creation 
of  conditions  favorable  for  the  spread  of  forest  fires.  Unfortu- 
nately most  of  the  factors  influencing  the  spread  and  severity 


SPREAD   AND    SEVERITY   OF   FOREST   FIRES  255 

of  forest  fires  cannot  be  influenced  by  silvicultural  treatment 
although  those  relating  to  the  presence  and  condition  of  in- 
flammable material  are  susceptible  to  partial  control. 

The  most  important  factors  governing  the  rate  of  spread 
and  the  severity  of  fires  are  Hsted  below  and  separately  dis- 
cussed. _  The  spread  and  severity  of  fires  are  so  interrelated 
as  to  warrant  consideration  together. 

Chief  Factors  Influencing  the  Spread  and  Severity  of  Forest  Fires 
Inflammable  material: 

Amount,  Dryness,  Density. 
Topography : 
Atmospheric  conditions : 

Wind,  Precipitation,  Humidity. 

Inflammable  Material.  —  Fires  are  dependent  both  for  their 
severity  and  rate  of  spread  upon  the  available  fuel^  supply. 
This  consists  of  the  humus,  fitter,  ground  cover,  underbrush, 
fallen  limbs  and  trees,  tops  left  after  logging  and  the  standing 
trees  large  and  smaU.  In  other  words  all  the  vegetable  prod- 
ucts fiving  or  dead  may  furnish  fuel  for  the  flames. 

Amount.  —  The  severity  of  the  fire  is  more  directly  de- 
pendent upon  the  amount  of  fuel  than  is  the  rate  of  spread. 
A  fire  may  run  rapidly  under  certain  conditions  even  if  the 
fuel  supply  is  scanty,  but  such  a  fire  cannot  be  a  severe  and 
damaging  one. 

Dryness.  —  "N^Tiile  in  a  forest  there  is  normally  a  super- 
abundance of  potential  fuel,  this  is  not  available  for  con- 
sumption unless  it  is  dry.  Dryness  then  is  often,  though  not 
invariably,  the  key  to  the  amount  of  available  fuel.  Certain 
parts  of  the  forest,  such  as  the  Hving  trees  and  shrubs,  rarely 
if  ever  dry  out  sufficiently  to  burn  readily.  Green  fofiage 
unless  of  a  resinous  nature  burns  with  difiiculty  even  in  pro- 


256  FOREST  PROTECTION 

tracted  dry  periods.  The  litter  composed  of  fallen  leaves  and 
twigs  dries  quickly  and  is  easily  kindled  by  a  spark.  Conifer- 
ous needles  burn  faster  and  create  a  hotter  lire  than  the  Htter 
from  broadleaved  trees.  Grasses  and  other  herbaceous  vege- 
tation become  as  dry  as  tinder  at  certain  times  of  the  year. 
During  extended  droughts  the  humus  and  even  deep  peaty 
deposits  in  swamps  may  become  thoroughly  dry.  Large 
limbs  and  dead  trees  do  not  dry  out  as  quickly  as  the  Htter  but 
ultimately  may  attain  an  exceedingly  dry  condition.  This  is 
particularly  true  with  standing  dead  trees  from  which  the 
bark  has  disappeared. 

Density.  —  The  uniformity  and  compact  arrangement  of 
the  inflammable  material  has  great  influence  on  the  spread 
and  severity  of  the  fire.  Fastest  spread  occurs  when  the 
material  is  of  Hght  inflammable  character,  and  arranged  uni- 
formly so  that  the  fire  suffers  no  check  but  not  so  compactly 
as  to  prevent  the  ready  access  of  air. 

Severity  of  the  fire,  other  conditions  being  equal,  increases 
with  the  density  of  material.  Density  makes  for  slow  ad- 
vance of  the  fire  but  keeps  the  fire  in  one  place  for  a  relatively 
long  time.  This  results  in  more  complete  consumption  of 
the  material  and  in  greater  injury.  For  example,  a  fire  burn- 
ing through  a  field  of  scrub  oak  brush  covered  with  dry  leaves 
will  rush  forward  rapidly;  but  much  material  will  be  uncon- 
sumed  and  injuries  to  standing  trees  may  be  slight  because 
the  flames,  though  hot,  do  not  remain  long  in  one  spot.  If 
this  same  brush  is  cut  and  left  lying  in  an  evenly  distributed 
compact  layer  on  the  ground  and  then  burned  at  the  same 
degree  of  dryness  as  when  standing,  the  fire  wiU  advance 
more  slowly,  consumption  of  material  wiU  be  more  complete 
and  injury  to  the  Hving  trees  greater. 

A  ground  fire  burning  in  finely  powdered  humus  with  re- 
stricted oxygen  supply  necessarily  burns  slowly  but  all  dry 


SPREAD   AND   SEVERITY  OF  FOREST  FIRES  257 

material  can  be  reached  and  consumed  and  all  trees  affected 
are  killed. 

A  crown  fire  burning  in  the  tree  tops  where  the  individual 
limbs  and  trees  are  frequently  not  touching  requires  a  high 
wind  to  carry  the  flames  from  point  to  point  and  very  dry 
easily  ignited  material.  It  may  kill  all  the  trees  in  its  path, 
but  yet  for  the  heat  units  produced  a  crown  fire  is  not  so 
destructive  as  a  quiet  burning  ground  fire  with  its  fine  grained 
material. 

Topography.  —  The  slope,  aspect  and  surface  conditions 
each  affect  spread  and  severity.  In  a  rugged  country,  due  to 
the  frequent  and  wide  variations  in  topography,  the  progress 
of  a  fire  is  extremely  irregular.  Regions  without  distinguish- 
ing topographic  features  favor  a  more  uniform  development  of 
all  sections  of  the  fire. 

A  fire  burning  uphill  advances  rapidly.  The  heated 
air  rising  vertically  and  radiating  horizontally^  passes  near 
(particularly  in  the  case  of  very  steep  slopes)  the  ground 
ahead  of  the  fire  and  by  its  heating  and  drying  action 
hastens  ignition  and  increases  the  intensity  of  the  fire. 
Trees  are  injured  worst  on  their  uphill  sides,  both  because 
humus  and  Ktter  are  apt  to  accumulate  there,  and  because 
the  flames  protected  by  the  tree  trunks  from  the  draft 
burn  longer  in  proximity  to  the  tree.  When  a  fire  runs  up  a 
slope  to  the  summit  of  a  narrow  ridge  burning  brands  are 
likely  to  be  carried  over  and  dropped  farther  ahead  than  is 
the  case  on  level  ground.  Fire  progresses  down  hill  very 
slowly  and  relatively  feebly,  burning  as  it  must  against  the 
upper  draft  of  heated  air.  Where  the  available  fuel  is  of 
such  a  character  as  to  roll  down  hill  easily,  burning  sticks  or 
cones  may  set  fires  some  distance  below  the  original  fires. 
Fires  so  set  are  apt  to  sweep  up  the  slope  quickly  until  they 
meet  the  other  fire.     Cones  furnish  the  most  dangerous  mate- 


258  FOREST  PROTECTION 

rial  for  carrying  fire  down  a  slope.  Where  slopes  become 
precipitous  and  barren  of  vegetation  they  form  effective  bar- 
riers to  the  spread  of  fire. 

A  stream  or  narrow  strip  of  moist  ground  at  the  bottom  of 
a  ravine  may  serve  to  stop  a  fire.  The  latter  has  burned 
slowly  down  the  slope  and  on  approaching  the  stream  has  not 
sufficient  momentum  to  leap  this  obstacle. 

Slopes  with  northern  aspect  do  not  suffer  so  severely  as 
those  with  southern  exposure.  This  is  explained  by  the  greater 
dryness  of  the  fuel  due  to  the  heat  of  the  sun  on  the  more 
exposed  southern  slopes. 

A  smooth  surface  on  which  the  inflammable  material  oc- 
curs uniformly  distributed  tends  to  make  the  fire  burn  more 
evenly  and  intensely.  Bare  rocks  tend  to  delay  and  break  up 
the  front  of  the  fire. 

Atmospheric  Conditions. — Atmospheric  conditions  in  in- 
fluencing forest  fires  act  either  through  affecting  the  dryness 
and  inflammability  of  the  fuel  or  by  fanning  the  flames  and 
increasing  the  speed  of  the  fire. 

Wind.  —  The  wind  is  a  factor  of  primary  importance  in 
determining  the  spread  and  severity  of  fires.  By  its  powerful 
drying  and  evaporating  action  it  increases  the  inflammability 
of  fuel  and  also  furnishes  the  draft  necessary  for  the  rapid 
spread  of  the  flames. 

The  velocity  of  the  wind  is  the  most  important  single  factor 
determining  the  rate  at  which  a  fire  advances. 

The  steadiness  of  the  wind  has  great  influence  particularly 
in  crown  fires.  For  such  fires  a  wind  of  high  velocity  is 
required  to  carry  the  flames  from  tree  to  tree.  It  must  also 
be  steady  because  when  the  wind  slackens  the  fire  dies  down 
in  the  tops  and  burns  along  the  surface,  from  which  it  may 
jump  to  the  crowns  when  the  wind  rises. 

The  occurrence  of  a  high  wind  may  be  inferred  as  an  ac- 


SPREAD   AND   SEVERITY  OF   FOREST  FIRES  259 

companiment  of  every  severe  surface  or  crown  fire.  Figures 
taken  from  the  report  of  the  State  Forester  of  Connecticut  for 
1 91 6  illustrate  the  effect  of  high  winds.  Two  weeks  of  dry 
windy  weather  culminating  in  two  days  of  high  winds  on 
May  nth  and  12th  proved  to  be  the  worst  fire  season  of  the 
year.  "Of  the  sixteen  fires  reported  during  the  year  as  ex- 
ceeding one  hundred  acres  in  extent,  ten  occurred  on  these 
two  days.  The  total  acreage  of  these  ten  fires  was  reported 
as  approximately  twelve  thousand,  —  nearly  60  per  cent  of 
the  entire  acreage  burned  in  the  state  during  the  year."  ^° 

Precipitation.  —  Moisture  is  the  controlling  factor  govern- 
ing the  inflammability  of  fuel.  During  rainy  periods  or 
seasons  when  the  ground  is  covered  with  snow  fires  rarely  if 
ever  are  able  to  run. 

In  seasons  of  low  precipitation  the  danger  from  fire  is  great 
and  rises  rapidly  with  a  lengthening  of  the  drouth.  Very 
sHght  precipitation  is  soon  evaporated  and  is  of  small  and 
temporary  value  in  reducing  inflammability. 

Relative  Humidity.  —  The  relative  humidity  of  the  atmos- 
phere has  an  important  effect  on  the  inflammability  of  fuel,^ 
since  the  latter  either  absorbs  moisture  from  the  air  as  the 
relative  humidity  rises  or  evaporates  moisture  as  it  falls.  The 
chief  significance  from  the  forest  fire  standpoint  of  cloudy 
versus  sunny  days,  of  hot  versus  cold  days  and  of  day  versus 
night  is  found  in  the  changes  in  relative  humidity  which  ensue. 

Methods  of  Forest  Fire  Protection.  —  The  methods  of  ob- 
taining protection  from  forest  fires  may  be  summarized  under 
four  heads. 

I.  The  ehmination  of  the  causes  from  which  forest  fires 
originate. 

As  the  gathering  of  statistics  on  forest  fires  has  progressed, 
the  numerous  causes  from  which  forest  fires  originate  have 
been  classified  under  eight  major  sources.     The  last  pubHshed 


26o  FOREST  PROTECTION 

figures  on  the  subject  are  those  arranged  by  J.  G.  Peters  " 
and  issued  by  the  United  States  Department  of  Agriculture 
for  the  calendar  year  191 5.  The  following  table  showing  the 
list  of  causes  together  with  the  percentage  of  the  total  num- 
ber of  fires  originating  from  each  cause  is  taken  from  this 
pubhcation. 

Causes  of  Forest  Fires  in  the  United  States  for  the  Calendar 

y   -^  Percentage  of 

Causes  the  total  num- 

ber of  fires. 

Lightning 14 

Railroads 15 

Lumbering 2 

Brush  burning 12 

Campers 12 

Incendiary 7 

Miscellaneous 10 

Unknown 28 

Total Too 

2.  The  reduction  of  the  fuel  (inflammable  material)  upon 
which  forest  fires  feed. 

3.  Quick  detection  of  the  forest  fires  which  start. 

4.  Prompt  suppression  of  the  forest  fires  discovered. 

To  what  extent  can  the  silvicultural  treatment  of  the  forest 
assist  toward  securing  fire  protection?  Assistance  can  be  ren- 
dered in  the  reduction  of  the  inflammable  material  available 
for  the  fires.  Close  utilization  of  defective  trees  and  the  dis- 
posal of  slash  as  described  in  Chapter  XIII,  will  remove  an 
important  class  of  inflammable  material.  Avoidance  of  large 
clearings  on  sites  with  a  high  fire  hazard  may  be  helpful.  The 
selection  method  of  reproduction  producing  an  unevenaged 
stand  with  a  constantly  maintained  cover,  thereby  protecting 
the  ground  cover  and  litter  from  excessive  drying  out,  tends 
to  reduce  the  inflammable  material  and  is  preferable  from  the 
fire  standpoint  to  other  reproduction  methods. 


REFERENCES  261 

Suppression  may  be  made  easier  by  the  disposal  of  slash, 
in  that  a  forest  unincumbered  with  slash  is  more  readily 
traversed  and  fires  more  effectively  fought  where  slash  is 
lacking. 

The  employment  of  severance  cuttings,  creating  cleared 
lines  at  intervals  throughout  the  forest,  also  serves  to  facili- 
tate access  and  affords  vantage  points  from  which  fire-fighting 
may  be  begun. 

Development  (by  artificial  regeneration)  of  belts  of  fire 
resistant  species,  parallel  to  railroad  lines  or  in  other  locations 
of  high  fire  hazard,  may  be  used  where  management  can  be 
intensive  for  preventing  the  start  or  spread  of  forest  fires. 

With  such  exceptions  as  have  just  been  given,  elimination 
of  the  causes,  quick  detection  and  prompt  suppression  of 
forest  fires  cannot  be  influenced  to  any  large  extent  by  silvi- 
cultural  treatment  of  the  forest. 

REFERENCES 

1.  Plummer,  Fred  G.  Forest  Fires.  Bulletin  117,  United  States  Forest 
Service,  Washington,  191 2. 

2.  Peters,  J.  G.  Forest  Fires  in  the  United  States  in  1915.  Circular  69, 
Office  of  Secretary,  United  States  Department  of  Agriculture,  191 7,  p.  3. 

3.  Oregon  Forest  Facts.     State  Board  of  Forestry,  Salem,  Oregon,  191 7. 

4.  Mayr,  Heinrich.  Waldbau  auf  Naturgesetzlicher  Grundlage.  Ber- 
lin, 1909,  p.  12. 

5.  Graves,  H.  S.  Principles  of  Handling  Woodlands.  Wiley  &  Sons, 
Inc.,  New  York,  191 1. 

6.  Long,  W.  H.  Effect  of  Forest  Fires  on  Standing  Hardwood  Timber 
Circular  216,  United  States  Forest  Service,  Washington,  1913. 

7.  NiSBET,  J.     Studies  in  Forestry.      Oxford,  1894.     Pp.  101-107. 

8.  Gary,  Austin.  Ticks  and  Timber.  American  Forestry,  Vol.  26,  1920, 
pp.  92-94. 

9.  Osborne,  W.  B.  Jr.  The  Western  Fire  Fighters  Manual,  Chapter 
VII,  Fire  Fighting,  1919,  pp.  17-22. 

10.  FiLLEY,  W.  O.  Report  of  the  Forester  in  Part  VI  of  the  Annual  Re- 
port for  1916  of  the  Connecticut  Agricultural  Experiment  Station,  New  Haven, 
p.  380. 


262  FOREST  PROTECTION 

II.  Peters,  J.  G.  Forest  Fires  in  the  United  States  in  1915.  Circular  69, 
Ofl&ce  of  the  Secretary,  United  States  Department  of  Agriculture,  Washington, 
1917,  p.  2. 

DuBois,  C.     Systematic  Fire  Protection  in  the  CaUfornia  Forests.    Forest 

Service,  United  States  Department  of  Agriculture,  Washington,  19 14. 
MxJNGER,  T.  T.     Western  Yellow  Pine  in  Oregon.     Bulletin  418,  United  States 

Department  of  Agriculture,  Washington,  1917,  pp.  9-12. 
SiLCOx,  F.  A.     Fire  Protection  in  District  I.     Forest  Service,  United  States 

Department  of  Agriculture,  Washington,  1915. 
Troup,  R.  S.    Pinus  Longifolia,  Roxb.    A  Sylvicultural  Study.    The  Indian 

Forest  Memoirs,  Vol.  I,  Part  I,  Silviculture  Series,  Calcutta,  1916,   pp. 

67-78. 


CHAPTER  XVI 
PROTECTION  AGAINST  INSECTS 

Extent  of  the  Damage  Caused  by  Insects.  —  The  extent  of 
the  annual  loss  due  to  insect  depredations  is  more  difficult  to 
accurately  estimate  than  the  fire  loss :  because  the  latter  sta- 
tistics (incomplete  to  be  sure)  are  gathered  by  nearly  all  for- 
estry organizations;  while  for  the  former  equally  detailed  rec- 
ords of  losses  are  unheard  of.  General  estimates  made  by 
entomologists  on  the  basis  of  observation  and  consultation 
with  other  experts  furnish  the  best  available  information.  Dr. 
A.  D.  Hopkins^  published  in  1910,  an  estimate  that  the  an- 
nual loss  in  the  United  States  from  forest  insect  depredations 
amounted  to  more  than  $100,000,000,  or  a  reduction  of  10  per 
cent  in  the  value  of  the  annual  output  of  forest  products  in  the 
rough.  His  estimate,  when  applied  only  to  the  value  of  the 
standing  timber  killed  and  damaged,  put  the  annual  loss 
based  on  a  ten  year  average)  at  $62,500,000.  These  figures 
do  not  include  damage  to  manufactured  forest  products. 

It  is  probable  that  insects  do  more  injury  in  the  average 
year  than  that  caused  by  forest  fires.^ 

Character  of  the  Injury.  —  Insect  depredations  range  from 
the  deforming,  weakening  or  destruction  of  single  trees  up  to 
the  killing  of  a  large  proportion  of  the  timber  in  regions  thou- 
sands of  square  miles  in  extent.^  ^"'^  ^  The  latter  type  of  injury 
may  be  readily  observed  but  damage  to  single  trees  and  small 
gi-oups  of  timber  often  goes  unnoticed,  although  in  the  aggre- 
gate it  must  reach  a  tremendous  total,  and  may  exceed  the 

loss  in  the  large  outbreaks. 

263 


264  PROTECTION  AGAINST  INSECTS 

Seed  crops  are  sometimes  destroyed  by  insects  working  in 
the  cones  and  seeds.  This  was  the  case  with  the  Norway 
pine  seed  crop  in  191 9,  throughout  northern  New  York. 
Insects  interfere  with  the  growing  of  plant  material  in  nur- 
series; they  may  destroy  reproduction  starting  on  cutover 
areas.  Numerous  species  prey  on  the  young  and  middle- 
aged  stands  and  are  a  constant  source  of  annoyance  and 
expense  to  the  forester  in  producing  forest  crops.  In  stands 
approaching  maturity  epidemics  are  Hkely  to  develop  which 
may  destroy  the  entire  stand. 

Every  part  of  the  tree  has  its  insect  enemies  and  each 
species  of  tree  is  likely  to  be  attacked  by  distinct  species. 

Insects  are  classed  by  Furst  ^  on  the  basis  of  the  part  of  the 
tree  attacked  into : 

Boring  insects,  which  bore  into  the  bark,  cambium  layer, 

sapwood,  heartwood  and  pith. 
DefoHating  insects,  which  destroy  foHage. 
Root  destroying  insects. 
Bud  destroying  insects. 
Seed  destroying  insects. 
Insects  which  produce  deformities  or  malformation. 

Each  insect  is  hkely  to  prefer  or  be  restricted  in  its  attack 
to  trees  of  a  certain  age;  either  pre3dng  upon  young  repro- 
duction, upon  sapHngs  and  poles,  or  upon  mature  individuals. 

The  injury  inflicted  may  be  of  a  physiological  or  of  a  tech- 
nical nature.^  Under  the  former  come  injuries  such  as  de- 
foHation  and  girdhng  which  interfere  directly  with  the  physi- 
ological Hfe  processes  of  the  tree;  while  under  the  latter  are 
included  injuries  such  as  those  by  wood  boring  insects,  which 
may  ruin  or  reduce  the  value  of  the  tree  for  commercial  prod- 
ucts but  which  do  not  interfere  directly  with  its  growth. 

Insect  epidemics  are  of  more  common  occurrence  and  of 


THE   CAUSES   OF  INSECT  ATTACKS  265 

more  serious  consequence  in  the  case  of  coniferous  than  in 
hardwood  forests.  Pure  stands  of  conifers  are  particularly- 
susceptible.  There  appear  to  be  two  reasons  for  the  greater 
damage  to  conifers.  First  more  species  and  more  destructive 
insects  attack  the  conifers;  and  secondly  conifers  do  not 
recover  so  easily  from  insect  injuries  as  do  hardwoods,  be- 
cause the  latter  replace  injured  parts  more  readily.^  As  an 
illustration,  complete  defoliation,  by  the  gipsy  moth  ordi- 
narily causes  death  of  a  conifer,  whereas  a  hardwood  tree  may 
survive  several  defoliations. 

The  killing  of  trees  by  insects  increases  the  amount  of  in- 
flammable material  in  the  forest  and  hence  the  fire  danger. 
Insect  epidemics  are  often  followed  by  disastrous  fires  made 
possible  by  the  fuel  in  the  insect  killed  trees.  On  the  other 
hand  fires  injuring  the  standing  timber  may  lead  to  the  de- 
velopment of  a  big  insect  outbreak,  altho  this  is  not  always 
the  caseJ  Insects  may  be  responsible  for  injuries  by  fungi, 
which  find  access  to  the  tree  through  the  galleries  and  holes  in 
the  bark. 

Insects  Responsible  for  the  Damage.  —  The  wood  boring 
insects,  particularly  the  bark  beetles  and  grubs,  constitute  one 
of  the  two  most  destructive  classes  of  insects;  while  defoHating 
insects  form  the  other."*  For  detailed  lists  and  descriptions 
of  injurious  (and  beneficial)  insects  the  literature  treating 
with  forest  insects  should  be  consulted. 

Forest  insects  may  be  classed  as  injurious,  beneficial  or 
neutral.  The  beneficial  insects  function  either  as  parasites 
living  within  injurious  insects  or  as  predaceous  insects  feed- 
ing externally  upon  the  injurious  insects.  Neutral  insects 
are  those  present  in  the  forest  which  have  no  distinctly 
beneficial  or  injurious  influence. 

The  Causes  of  Insect  Attacks.  —  Insects  attack  trees  for 
one  of  two  purposes;    either  to  obtain  food  of  which  defoli- 


266  PROTECTION  AGAINST  INSECTS 

ating  insects  furnish  examples,  or  to  secure  places  to  breed, 
as  is  the  case  with  certain  bark  beetles.  More  species  of 
insects  occur  in  warm  climates  and  at  low  elevations  than  at 
high  altitudes  and  cold  climates. 

Within  the  last  three  decades  attention  has  been  called  to 
insect  depredations  because  of  the  awakening  of  interest  in 
forestry.  But  extensive  insect  attacks  are  not  of  recent  ori- 
gin. Insects  were  always  present  in  the  forest  and  at  inter- 
vals developed  sufficiently  to  cause  widespread  destruction.'* 
Under  ordinary  conditions  a  given  species  of  insect  will  be 
found  occurring  in  relatively  small  numbers,  attacking  single 
trees  or  small  groups  of  trees  here  and  there  throughout  the 
forest.  When  for  some  reason  conditions  become  particu- 
larly favorable  for  rapid  multiphcation,  the  insects  may  in- 
crease enormously  in  numbers  and  extend  their  ravages  until 
a  considerable  portion  of  the  timber  over  a  large  area  is 
attacked. 

Causes  for  such  infestations  existed  in  the  original  forest 
long  before  the  country  was  settled  by  man.  Hopping,^  on 
page  2  of  his  "Manual  of  Insect  Control  for  California," 
states  that:  "In  the  past,  epidemics  of  infestation  were  prob- 
ably caused  by  high  winds  uprooting  or  breaking  trees,  light- 
ning, fires,  snowbreak,  etc.,  or  by  favorable  climatic  condi- 
tions. Man  has  now  supplied  other  causes  such  as  uncon- 
trolled fellings,  girdled  trees,  cull  logs,  hmbs  and  brush  left 
over  one  season.  Many  of  the  brush  openings  in  timber 
supposed  to  be  caused  by  fire  are  primarily  the  result  of 
epidemics  of  insect  infestations." 

It  is  evident  that  the  chances  for  insect  outbreaks  on  a 
large  scale  must  be  increased  through  the  operation  of  the 
new  and  additional  causes  which  have  followed  in  the  train 
of  settlement,  and  that  if  such  outbreaks  are  not  to  occur, 
preventive  or  control  measures  must  be  undertaken. 


METHODS  OF  CONTROL  AND  PREVENTION      267 

Up  to  the  present  time  such  measures  have  not  been  under- 
taken on  an  adequate  scale  and  insect  epidemics  have  be- 
come more  frequent.  Where  the  epidemics  occur  in  mature 
timber  the  loss  at  the  present  day  should  be  far  less  than  in 
the  past,  because  logging  operations  can  be  directed  so  as  to 
utilize  the  insect  injured  timber.  Extensive  attacks  upon 
reproduction  and  middle  aged  timber  or  to  inaccessible  bodies 
of  mature  timber  afford  the  greatest  hazard  because  such 
losses  cannot  be  salvaged. 

Methods  of  Control  and  Prevention.  —  Eventually  the  ne- 
cessity of  developing  a  systematic  plan  for  the  control  and 
prevention  of  injury  by  insects  will  be  accepted  as  just  as 
fundamental  as  is  similar  action  to  secure  fire  protection. 

The  intensive  methods  of  prevention  and  control  possible 
in  the  protection  of  shade  and  orchard  trees  cannot  be  applied 
to  forest  crops,  because  of  their  high  cost  in  relation  to  the 
value  of  the  resource  threatened.  Dr.  Hopkins^  estimates 
that  at  least  30  per  cent  of  the  estimated  loss  due  to  insects 
can  be  controlled  or  prevented  by  proper  forest  management 
without  appreciable  extra  cost. 

The  complete  extermination  of  an  injurious  insect  is  prac- 
tically impossible.  As  Hopkins  ^  explains  this  is  unneces- 
sary. "Experience  has  demonstrated  that  it  is  only  neces- 
sary to  reduce  and  weaken  its  forces  75  per  cent  or  more.  It 
cannot  then  continue  an  aggressive  attack,  but  must  occupy 
a  defensive  position  against  its  own  enemies  until  conditions 
resulting  from  avoidable  negligence  and  mismanagement  by 
the  owners  of  the  forests  and  manufacturers  of  forest  products 
favor  its  again  becoming  destructive." 

Methods  of  prevention  and  control  may  be  summarized 
under  the  following  headings: 

(a)  Protection  and  increase  of  the  natural  enemies  of  the 
injurious  insects. 


268  PROTECTION  AGAINST   INSECTS 

So  far  as  possible  natural  agencies  which  control  insects 
should  be  fostered.  This  will  include  the  protection  and  aug- 
mentation in  numbers  of  beneficial  insects,  mammals,  birds 
and  diseases  which  destroy  injurious  insects. 

Of  these  the  beneficial  insects  are  apt  to  be  the  most  effec- 
tive single  natural  factor  for  control.  Insect  diseases  (such 
as  the  wilt  disease  of  the  gipsy  moth  ^)  may  suddenly  destroy 
vast  numbers  of  insects;  but  such  diseases  only  become 
virulent  when  the  insect  numbers  have  increased  to  an  enor- 
mous total.  Hence  diseases  do  not  check  insect  epidemics 
until  extensive  injury  has  taken  place.  Birds  may  be  effective 
in  preventing  the  start  of  an  epidemic,  but  will  be  too 
few  in  number  to  cope  with  a  serious  outbreak  when  once 
started. 

Dr.  Felt  ^°  says  in  Volume  I,  page  25,  of  his  book  entitled 
"Insects  affecting  Park  and  Woodland  Trees  ":  "The  control 
of  insects,  particularly  in  forests,  must  be  effected  very  largely 
through  the  activity  of  natural  agents,  which  should  be  en- 
couraged in  every  possible  way.  It  is  ordinarily  impractical 
to  attempt  much  in  either  a  preventive  or  a  remedial  way,  in 
the  forests  of  the  United  States."  In  view  of  the  insect  con- 
trol and  prevention  work  which  has  been  successfully  con- 
ducted by  the  United  States  Forest  Service  and  other  organ- 
izations, it  would  seem  that  Dr.  Felt's  last  statement  presents 
a  pessimistic  viewpoint. 

(b)  Disposal  of  slash  and  other  material  in  which  insects 
find  favorable  conditions  for  breeding. 

Insects  breed  in  all  parts  of  the  slash  but  particularly  in 
the  larger  sized  portions.  The  stumps  of  felled  trees,  trees 
windthrown  or  broken  by  snow  and  standing  trees  in  un- 
healthy condition,  offer  good  breeding  places.  Trees  already 
infested  with  insects  but  not  taken  in  a  logging  operation 
require  treatment. 


METHODS  OF  CONTROL  AND  PREVENTION      269 

On  cutover  areas  slash  and  stumps  furnish  the  principal 
breeding  places.  In  areas  of  uncut  timber  the  scattered 
trees  or  groups  of  trees  already  infested  with  insects  are  the 
ones  to  be  treated. 

The  details  of  treatment  for  the  slash  and  standing  trees 
must  be  worked  out  scientifically  to  meet  the  circumstances 
of  each  individual  case.  In  general  all  small  material  can  be 
completely  burned,  while  large  portions  of  the  trunk  and 
Hmbs  should  have  the  bark  peeled  and  burned  in  such  a  way 
as  to  thoroughly  char  the  peeled  logs.  They  then  become 
unfavorable  breeding  places.  Stumps  may  have  to  be  peeled 
down  to  the  ground  and  charred  by  having  the  peeled  bark 
burned  in  proximity  to  the  stump.  Standing  trees  may  be 
felled  and  treated  as  just  described  or  left  standing  and  a 
portion  of  the  trunk  of  the  standing  tree  peeled  of  bark. 
With  some  species,  such  as  the  southern  pine  beetle,"  it  may 
be  unnecessary  to  peel  the  stump  or  the  entire  trunk. 

Other  effective  methods  of  disposing  of  insect  infested  ma- 
terial are  to  place  the  logs  in  water,  utilize  the  trees  for  cord- 
wood  or  to  cut  the  logs  into  lumber  and  burn  the  slabs  and 
bark  before  the  insects  emerge. 

The  peeHng  and  burning  is  most  effective  if  accompHshed 
after  the  insects  have  entered  but  before  they  have  emerged 
from  the  slash,  stumps,  or  standing  trees.  Sometimes  so 
called  "trap"  trees  may  be  felled  for  the  purpose  of  attracting 
insects.  The  insects  prefer  this  freshly  cut  material  and  will 
enter  such  trees  and  be  destroyed  in  the  subsequent  peehng 
and  burning  operations. 

When  branches  or  terminal  shoots  of  young  trees  are  at- 
tacked by  boring  insects  (as  in  the  case  of  the  white  pine 
weevil,  Pissodcs  strobi),  the  injured  portions  may  be  cut  off 
and  burned;  and  in  the  case  of  seedhngs  the  entire  plants 
may  be  pulled  up  and  destroyed. 


270  PROTECTION   AGAINST  INSECTS 

(c)  Special  silvicultural  measures  to  prevent  the  creation 
of  conditions  favorable  to  injurious  insects. 

Since  most  species  of  insects  prefer  unhealthy,  weakened 
trees  in  which  to  breed,  it  follows  that  efforts  should  be 
directed  toward  maintaining  the  forest  crop  in  a  healthy  condi- 
tion. If  possible  thinnings  should  be  made  early  and  re- 
peated frequently.  All  unhealthy  trees  should  be  cut.  In 
mixed  stands,  where  there  is  a  difference  in  susceptibility 
among  the  species  in  mixture  to  the  attacks  of  a  dangerous 
insect,  present  or  likely  to  appear,  thinnings  and  other  cut- 
ting operations  can  be  directed  toward  the  removal  of  the 
species  most  liable  to  injury.^  This  is  the  principal  and  most 
practicable  measure  for  controlling  the  gipsy  moth  in  the 
forest.13  ^^'^  ^* 

The  fertility  of  the  site  should  be  improved  if  possible  of 
accomplishment.  This  is  especially  desirable  on  dry  warm 
sites,  for  in  such  localities  insects  thrive.  Large  clearings, 
particularly  when  they  are  to  be  restocked  with  pure  conifer- 
ous stands,  should  be  avoided.  To  reduce  insect  injury  small 
cutover  areas  and  mixed  stands  are  desirable. 

In  foreign  countries  intensive  methods  of  collecting  and 
destro>dng  the  insects  in  the  egg,  larva,  pupa  or  final  stages 
by  means  of  hand  picking,  various  trapping  devices,  such  as 
bands  of  viscous  substances  encircling  the  tree  trunks,  the 
use  of  trenches,  lights,  etc.,  have  been  employed.  Similar 
methods  are  already  used  on  a  limited  scale  in  the  United 
States  principally  in  connection  with  nursery  management. 

The  value  of  the  timber  protected  must  be  high  to  justify 
such  methods  of  control  in  the  forest. 

The  development  of  effective  control  and  preventive  meas- 
ures requires  detailed  knowledge  of  the  local  habits  of  the 
injurious  insects  which  is  best  secured  by  a  forest  entomologist. 

The  local  forester  can  quickly  learn  the  essential  facts  for 


REFERENCES  271 

his  forest.  It  is  imperative  that  he  be  always  on  the  lookout 
for  signs  of  insect  depredations  and  discover  the  attack  before 
it  has  reached  a  serious  stage.  There  are  various  signs  by 
which  insects  reveal  their  presence,  such  as  fine  dust  from 
their  borings  on  the  ground  or  on  tree  trunks,  holes  in  the 
tree  trunks,  excrement,  exudation  of  pitch,  the  withering  or 
coloring  of  foliage,  a  bare  appearance  of  the  tree  tops,  bitten 
off  and  partially  devoured  foliage  on  the  ground,  and  the 
presence  in  the  stand  of  an  unusually  large  number  of  in- 
sectivorous birds. 

REFERENCES 

1.  Hopkins,  A.  D.  Insects  in  Their  Relation  to  the  Reduction  of  Future 
Supplies  of  Timber,  and  General  Principles  of  Control.  Circular  No.  129, 
Bureau  of  Entomology,  U.  S.  Department  of  Agriculture,  Washington,  1910. 

2.  Pearce,  W.  J.  The  Relation  of  Insect  Losses  to  Sustained  Forest 
Yield.     Journal  of  Forestry,  Vol.  XVIII,  1920,  pp.  406-411. 

3.  Hopkins,  A.  D.  On  the  Study  of  Forest  Entomology  in  America. 
Bulletin  37,  N.  S.  Division  of  Entomology,  U.  S.  Department  of  Agriculture 
(Proc.  14th  Annual  Meeting  Assn.  Econ.  Ent.),  Washington,  1902,  pp.  20-25. 

4.  Hopkins,  A.  D.  Notable  Depredations  by  Forest  Insects.  Yearbook 
of  U.  S.  Department  of  Agriculture  for  1907,  Washington,  1908,  pp.  149-164. 

5.  FuRST,  H.  The  Protection  of  Woodlands,  translated  by  John  Nisbet, 
Edinburgh,  1893,  pp.  129-130. 

6.  Fisher,  W.  R.  Forest  Protection.  Schlich's  Manual  of  Forestry, 
Vol.  IV,  London,  1895,  p.  140. 

7.  Report  of  the  Entomologist  for  1919.  U.  S.  Department  of  Agri- 
culture, Washington,  1919,'  p.  12. 

8.  Hopping,  Ralph.  Manual  of  Insect  Control  for  California  District  5, 
1914.     Manuscript. 

9.  Reiff^  William.  The  Wilt  Disease  or  "Flacherie"  of  the  Gipsy 
Moth.  Published  under  the  direction  of  F.  W.  Rane,  State  Forester,  Boston, 
Mass.,  1911. 

10.  Felt,  E.  P.  Insects  Affecting  Park  and  Woodland  Trees.  New  York 
State  Museum,  Memoir  8,  2  vols.  Albany,  1905-06.  (Includes  BibUography 
for  each  of  the  insects  described.) 

11.  Hopkins,  A.  D.  The  Dying  of  Pine  in  the  Southern  States:  Cause, 
Extent  and  Remedy.  Farmers'  Bulletin  No.  476,  U.  S.  Department  of  Agri- 
culture, Washington,  1911. 

12.  FiSKE,  W.  F.     The  Gipsy  Moth  as  a  Forest  Insect,  with  suggestions 


2^: 


PROTECTION  AGAINST   INSECTS 


as  to  its  control.     Circular  164,  Bureau  of  Entomology,  U.  S.  Department  of 
Agriculture,  Washington,  1913. 

13.  Burgess,  A.  F.  The  Gipsy  Moth  and  the  Brown-tail  Moth  and  Their 
Control.  Farmers'  Bulletin  845,  U.  S.  Department  of  Agriculture,  Washing- 
ton, 1917,  p.  22. 

14.  Clement,  G.  E.  and  Munro,  Willis.  Control  of  the  Gipsy  Moth  by 
Forest  Management.  Bulletin  484,  United  States  Department  of  Agriculture, 
Washington,  191 7. 

Brunner,  Josef.     The  Zimmerman  Pine  Moth.     Bulletin  295,  U.  S.  Depart- 
ment of  Agriculture,  Washington,  1915. 
Burgess,  A.  F.  and  Collins,  C.  W.    The  Value  of  Predaceous  Beetles  in 

Destroying  Insect  Pests.     Yearbook,  U.  S.  Department  of  Agriculture 

for  1911,  Washington,  1912,  pp.  453-466. 
Burgess,  A.  F.     The  Dispersion  of  the  Gipsy  Moth.     Bulletin  119,  Bureau  of 

Entomology,  U.  S.  Department  of  Agriculture,  Washington,  1913. 
Burgess,  A.  F.     Report  on  the  Gipsy  Moth  Work  in  New  England.     Bulletin 

204,  United  States  Department  of  Agriculture,  Washington,  1915. 
Burgess,  A.  F.     Suppression  of  the  Gipsy  and  Brown-tail  Moths  and  Its 

Value  to  States  not  Infested.     Separate  No.  706  from  the  Yearbook  of 

the  U.  S.  Department  of  Agriculture,  Washington,  191 7. 
Burke,  H.  E.     Injuries  to  Forest  Trees  by  Flat-headed  Borers.     Yearbook 

U.  S.  Department  of  Agriculture  for  1909.     Washington,  1910  pp.  399-415. 
Burke,  H.  E.     Flat-headed  Borers  Affecting  Forest  Trees  in  the  United 

States.     Bulletin  437,  U.  S.  Department  of  Agriculture,  Washington,  191 7. 
BuscK,  August.     The  European  Pine  Shoot  Moth;   a  Serious  Menace  to  Pine 

Timber  in  America.     Bulletin   170,   U.   S.   Department  of  Agriculture, 

Washington,  191 5. 
Collins,  C.  W.     Dispersion  of  Gipsy-Moth  Larvae  by  the  Wind.     Bulletin 

273,  U.  S.  Department  of  Agriculture,  Washington,  191 5. 
Cook,  H.  O.  and  Kneeland,  P.  D.     Instructions  for  Making  Improvement 

Thinnings  and  the  Management  of  Moth-Infested  Woodlands.     Pubhshed 

under  the  direction  of  F.  W.  Rane,  State  Forester,  Boston,  Mass.,  1914, 

pp.  16-29. 
Fisher,  R.  T.  and  Terry,  E.  I.     The  Management  of  Second  Growth  White 

Pine  in  Central  New  England.     Journal  of  Forestry,  Vol.  XVIII,  1920, 

pp.  363-364- 
Graham,  S.  A.     The  White  Pine  Weevil  and  Its  Relation  to  Second  Growth 

White  Pine.     Journal  of  Forestry,  Vol.  XVI,  1918,  pp.  192-202. 
Graham,    S.    A.      The    Place    of    Entomology    in    Forest   Working   Plans. 

Minnesota  Forest  School  Annual,  1920.      St.  Paul,  1920,  pp.  27-32. 
Haasis,  F.  W.     Dying  of  Young  Pines  in  Circles  about  Anthills.      Journal 

of  Forestry,  Vol.  XV,  191 7,  pp.  763-769. 


REFERENCES  273 

Hawley,  R.  C.  and  Record,  S.  J.     Do  Ants  Kill  Trees  About  Their  Colonies? 

American  Forestry,  Vol.  22,  1916,  pp.  685-6. 
Hopkins,  A.  D.     Insect  Enemies  of  Forest  Reproduction.     Yearbook  of  De- 
partment of  Agriculture,  Washington,  1905.     pp.  249-256. 

Hopkins,  A.  D.  and  Webb,  J.  L.  Some  Insects  Injurious  to  Forests.  Bulle- 
tin 58,  Bureau  of  Entomology,  U.  S.  Department  of  Agriculture,  Wash- 
ington, 1910. 

Hopkins,  A.  D.  Contributions  toward  a  Monograph  of  the  Bark-Weevils  of 
the  Genus  Pissodes.  Technical  Series,  No.  20,  Part  i,  Bureau  of  Ento- 
mology, U.  S.  Department  of  Agriculture,  Washington,  1911. 

Hopkins,  A.  D.  Insect  Injuries  to  Hardwood  Forest  Trees.  Yearbook  of 
Department  of  Agriculture  for  1903.     Washington,  1904,  pp.  313-328. 

Hopkins,  A.  D.  Damage  to  the  wood  of  fire-killed  Douglas  fir  and  methods  of 
preventing  losses,  in  western.  Washington  and  Oregon.  Circular  159, 
Bureau  of  Entomology,  U.  S.  Department  of  Agriculture,  Washington, 
1912. 

Hopkins,  A.  D.  Report  on  Investigations  to  Determine  the  Cause  of  Un- 
healthy Conditions  of  the  Spruce  and  Pine  from  1880-1893.  Bulletin  56, 
West  Virginia  Agricultural  Experiment  Station,  Morgantown,  1899. 

Hopkins,  A.  D.  Insect  Enemies  of  the  Spruce  in  the  Northeast.  Bulletin  28, 
N.  S.  Division  of  Entomology,  U.  S.  Department  of  Agriculture,  Wash- 
ington, 1901,  pp.  1-48. 

Hopkins,  A.  D.  Bark  Beetles  of  the  Genus  Dendroctonus.  Bull.  83,  Part  i. 
Bureau  of  Entomology,  U.  S.  Department  of  Agriculture,  Washington, 
1909. 

Hopkins,  A.  D.  The  Genus  Dendroctonus.  Technical  Series  No.  17,  Part  i. 
Bureau  of  Entomology,  U.  S.  Department  of  Agriculture,  Washington, 
1909. 

Hopkins,  A.  D.  Preliminary  Classification  of  the  superfamily  Scolytoidea 
Technical  Series,  No.  17,  pt.  2,  Bureau  of  Entomology,  U.  S.  Department 
of  Agriculture,  Washington,  1915. 

Marlatt,  C.  L.  The  Annual  Loss  Occasioned  by  Destructive  Insects  in  the 
United  States.  Yearbook,  U.  S.  Department  of  Agriculture  for  1904, 
Washington,  1905,  pp.  461-474. 

MOSHER,  F.  H.  Food  Plants  of  the  Gipsy  Moth  in  America.  Bulletin  250, 
U.  S.  Department  of  Agriculture,  Washington,  191 5. 

SwATNE,  J.  M.  Canadian  Bark-Beetles.  Descriptions  of  New  Species. 
Part  I,  Bulletin  14  (Technical  Bulletin),  Entomological  Branch,  Depart- 
ment of  Agriculture,  Dominion  of  Canada.     Ottawa,  191 7. 

SwATNE,  J.  M.  Canadian  Bark-Beetles.  A  Prehminary  Classification,  with 
an  Account  of  the  Habits  and  Means  of  Control.  Part  I,  Bulletin  14 
(Technical  Bulletin),  Entomological  Branch,  Department  of  Agriculture, 
Dominion  of  Canada.     Ottawa,  191 8. 


CHAPTER  XVII 
PROTECTION  AGAINST  TREE  DISEASES 

Fungi.  —  The  tree  diseases  of  greatest  importance  from  the 
silvicultural  standpoint  are  induced  by  parasitic  plants, 
principally  fungi.  Chief  consideration  will  be  directed  to 
diseases  of  this  class. 

The  silviculturist  is  interested  primarily  in  parasitic  fungi, 
in  contrast  to  saprophytic  fungi  since  the  latter  attacking 
only  dead  or  dying  material  are  not  the  cause  of  tree  diseases. 

For  a  comprehensive  account  of  all  classes  of  tree  diseases 
reference  should  be  had  to  books  devoted  to  the  subject  such 
as  those  by  Hartig  ^  ^'^^  ^  and  Rankin.^ 

Parasitic  fungi  are  able  to  attack  living  trees,  but  must 
have  a  suitable  opportunity  for  gaining  access.  In  young 
trees,  before  the  formation  of  cork  in  the  bark  is  accompHshed, 
fungi  are  able  to  gain  access  through  the  uninjured  bark,  if 
climatic  conditions  are  favorable.  Older  trees  can  be  attacked 
only  through  a  wound  or  opening  in  the  protective  bark 
covering.  Such  wounds  may  be  created  in  a  variety  of  ways; 
as  for  example  by  fires,  lightning,  frost,  storms,  insects  or 
branch  stubs  left  by  natural  pruning.  With  western  white 
pine,  branch  stubs  furnish  the  principal  points  for  attack;  ^ 
with  white  fir  (abies  concolor)  fire,  frost  and  lightning  are 
largely  responsible.^ 

The  presence  of  fungi  is  revealed  readily  by  the  appear- 
ance of  the  fruiting  bodies  springing  from  the  soil  or  parts  of 
the  tree  above  the  ground.  Where  sporophores  are  lacking 
there  may  still  be  fungi  within  the  trees.  Swellings,  or  pitch 
274 


FUNGI  275 

flows  from  branch  stubs  serve  as  indications,  while  soundings 
on  the  trunk  often  furnish  information.  An  increment  borer 
is  useful  for  taking  borings  to  determine  the  internal  condi- 
tion of  the  tree. 

A  humid  atmosphere,  at  least  in  the  zone  in  which  the 
fungi  are  developing,  favors  their  growth  because  both  the 
mycehum  and  the  sporophores  dry  out  very  easily  and  require 
large  amounts  of  water. 

The  regions  where  fungi  are  found  in  greatest  profusion 
have  humid,  relatively  warm  cKmates,  which  produce  a  dense 
forest;  and  within  such  regions  the  stands  growing  on  damp 
soils  are  likely  to  show  the  greatest  injury.  The  effect  of 
climatic  factors  such  as  temperature,  sunlight,  and  moisture 
apparently  is  not  the  same  for  all  "groups  of  fungi  ^  ^^^  ^  and 
still  furnishes  a  field  for  investigation.  With  advancing  age 
the  amount  of  injury  and  the  production  of  sporophores 
increases.* 

Extent  and  Character  of  the  Injury.  —  Both  insects  and  fire 
are  more  destructive  in  their  effects  upon  the  forest  than 
are  fungi.  Yet  the  latter  have  the  capacity  for  inflicting 
injury  on  a  large  scale.  Witness  the  chestnut  blight,  Endo- 
thia  parasitica,  which  has  exterminated  commercially  the 
chestnut  {Castanea  dentatd)  over  thousands  of  square  miles 
along  the  Atlantic  seaboard  in  a  period  of  less  than  20  years. 
The  rapidity  of  this  attack  and  the  completeness  of  the 
destruction  over  a  large  region  are  not  characteristic  of  the 
work  of  most  species  of  fungi. 

On  the  average  they  work  more  slowly  than  fire  and  in- 
sects, are  disseminated  unnoticed,  may  exist  within  their  tree 
hosts  for  many  years  before  revealing  their  presence  and  often 
consume  several  decades  in  accomplishing  the  death  and 
destruction  of  a  single  tree. 

The  extent  of  the  damage  caused  by  fungi  is  more  difficult 


276  PROTECTION  AGAINST  TREE  DISEASES 

to  determine  than  for  forest  insects  and  published  figures 
mainly  refer  to  losses  for  single  species  and  specified  regions. 
Estimates  of  the  loss  on  individual  areas  are  already  being  made 
with  reasonable  accuracy  ^  by  forest  pathologists.  Weir,'^  in 
1909,  estimated  the  loss  to  the  merchantable  stand  of  western 
white  pine  alone  to  be  in  excess  of  $7,000,000  annually. 

The  injury  (as  with  insects)  may  be :  —  either,  of  a  physio- 
logical nature,  resulting  in  interference  with  the  life  processes 
of  the  tree  and  the  death  or  deformation  of  a  part  or  the  whole 
tree;  or  of  a  technical  character  resulting  in  injury  to  the 
commercial  products  in  the  tree,  but  not  necessarily  inter- 
fering with  the  life  processes,  at  least  until  the  technical  value 
of  the  tree  is  practically  destroyed.  All  parts  of  the  tree 
may  be  attacked  both  above  and  below  the  ground  by  one  or 
more  of  the  numerous  species  of  fungi.  Rankin^  divides 
tree  diseases  into : 

Seedling  diseases  and  injuries, 

Leaf  diseases  and  injuries. 

Body  and  Branch  diseases  and  injuries,  and 

Root  diseases  and  injuries. 

The  seriousness  of  the  damage  varies  greatly  with  the  type 
of  fungus.  "Of  most  consequence  are  those  epidemic  dis- 
eases of  fungoid  origin  which  cause  rapid  death  of  their  host, 
and  spread  with  great  rapidity  over  wide  areas.  Such,  through 
repeated  attacks,  may  render  the  cultivation  of  certain  plants 
impossible  in  a  locality."  This  quotation  from  Tubeuf  ^  indi- 
cates his  judgment  as  to  the  most  destructive  type  of  fungi. 
Wood  destroying  fungi  he  classes  as  nearly  equal  in  the  losses 
caused. 

The  destructiveness  of  the  former  classes  of  diseases  '°  hes 
in  the  fact  that  they  may  kill  outright  trees  of  all  ages  com- 
mercially exterminating  a  species.     Where   the  species  ex- 


FUNGI  277 

terminated  is  the  chief  tree  for  management  in  the  region,  as 
was  the  case  with  the  chestnut  on  the  eastern  seaboard,  the 
loss  is  directly  to  the  productive  power  of  the  entire  forest 
area.  Wood  rotting  fungi,  while  they  may  totally  destroy 
the  timber  value  of  the  stand,  require  decades  to  accompHsh 
this,  and  do  not  attack  the  trees  until  fairly  well  along  in  Hfe, 
since  they  attack  the  heartwood  which  is  not  formed  in 
youth.  Their  destruction  of  timber  in  the  virgin  forest  may 
be  enormous,  but  in  the  managed  forests,  which  will  follow 
present  day  cuttings  and  can  be  harvested  while  still  relatively 
sound,  the  loss  can  be  kept  within  reasonable  bounds. 

In  addition  to  these  two  types  other  less  important  species 
cause  partial  injuries  or  deformities  which  at  the  least  result 
in  loss  of  increment.^  The  action  of  root  destroying  fungi  is  a 
large  factor  in  accounting  for  losses  from  wind.^^ 

The  influence  of  fungi  is  not  entirely  injurious.  They  may 
be  beneficial  in  destroying  harmful  insects  and  in  accompHsh- 
ing  the  rotting  of  the  slash,^  thereby  reducing  the  fire  hazard 
and  increasing  the  humus  supply. 

Methods  of  Control  and  Prevention.  —  Tree  diseases  cannot 
be  controlled  by  fostering  their  enemies  for  practically  none 
such  exist.  Against  most  species  of  fungi  direct  action  is 
impracticable  due  to  the  expense  involved.  General  silvi- 
cultural  measures  comprise  keeping  the  stand  in  thrifty  con- 
dition, the  use  of  thinnings,^^  avoiding  the  making  of  wounds 
on  the  trees  and  eliminating  infected  trees. 

One  of  the  two  most  destructive  tj^es,  namely  the  wood- 
rotting  fungi  causing  heart  rots,  can  be  partially  controlled. 
The  control  work  actually  executed  in  the  United  States  has 
been  conducted  principally  against  the  chestnut  blight,  the 
white  pine  blister  rust,  fungi  causing  heart-rots,  or  nursery 
diseases  of  coniferous  seedhngs.  A  discussion  of  the  latter 
may  be  relegated  to  the  realm  of  nursery  management. 


278  PROTECTION  AGAINST  TREE   DISEASES 

Fungi  causing  heart-rots  can  be  controlled  in  the  timber 
crops  succeeding  the  present  one  by  the  methods  outUned 
below: 

(a)  Use  of  a  rotation  sufficiently  short  so  that  the  heart-rots 
do  not  have  the  opportunity  to  destroy  more  than  a  small 
percentage  of  the  timber. 

(b)  Prevention  of  infection  of  the  new  crops. ^^  This  is 
likely  to  require: 

1.  Disposal  or  treatment  of  the  infected  slash  in  such  a 
manner  as  to  prevent  the  production  of  sporophores.  (See 
page  235.)  Slash  can  be  treated  either  by  the  use  of  fire  or 
methods  which  will  insure  its  dryinj,  out  and  thus  check 
development  of  the  fungi. ^^ 

2.  Felling  of  all  standing  infected  trees  and  treatment  as 
given  under  i. 

3.  The  retention  of  thrifty  trees  free  from  infection,  if  a 
portion  of  the  old  stand  is  left  for  seeding  purposes. 

The  white  pine  bHster  rust/^  cronartium  Ribicola,  intro- 
duced from  Europe  previous  to  1909,  has  threatened  within 
the  last  ten  years  to  develop  into  an  epidemic  similar,  though 
less  rapid  in  its  spread,  to  the  chestnut  blight.  The  methods 
of  control  ^^  consist  in  removing  all  species  of  ribes,  one  of  the 
hosts  of  the  disease,  and  thus  restricting  its  spread.  The 
cost  per  acre  of  eradicating  ribes  ^^  averages  less  than  $0.54 
per  acre  and  will,  as  methods  of  work  improve  and  are 
standardized,  be  lowered  appreciably. 

Re-eradication  every  five  to  ten  years  appears  to  be  neces- 
sary but  at  costs  lower  than  that  of  the  first  eradication. 
Eventually  eradication  of  ribes  must  be  considered  a  regular 
operation  in  growing  eastern  white  pine  and  be  pursued  sys- 
tematically. While  termed  "eradication"  the  work  in  reality 
reduces  the  quantity  of  ribes  in  a  given  area,  but  should  not 
be  expected  to  secure  absolute  eradication. 


TREE   DISEASES   AND   INJURIES  279 

Other  diseases  may  in  the  future  warrant  similar  measures 
of  control. 

Efforts  to  control  the  chestnut  blight,  although  pursued  for 
some  years  involving  large  expenditures  of  money,  were  ill- 
advised  and  resulted  in  abandonment  of  the  work. 

Tree  Diseases  and  Injuries  Other  than  Those  Produced  by 
Fungi.  —  Among  tree  diseases  and  injuries  not  previously 
considered  may  be  mentioned  stagheadedness,  root-rot,  ab- 
normal needle  shedding,  injury  by  acid  fumes  ^^  from  smelters 
and  other  manufacturing  plants,  bark-scorching  and  crack- 
ing, injuries  from  frost,  hail,  snow,  wind  and  hghtning. 

In  a  practical  way  little  can  be  done  to  control  or  prevent 
these  diseases  and  injuries. 

Protection  against  frost  should  be  assured  to  the  reproduc- 
tion of  sensitive  species  by  affording  shelter  in  early  youth. 
For  such  species  the  shelterwood  or  selection  methods  of 
reproduction  are  advantageous.  Early  frosts  in  the  fall  and 
late  frosts  in  the  spring  are  particularly  to  be  guarded  against. 
Injury  consists  in  the  freezing  of  seedlings  and  young  organs 
on  older  trees,  uprooting  of  seedlings  and  production  of  frost 
cracks  and  cankers. 

To  prevent  injury  from  bark-scorching,  exposure  on  the 
southern  and  western  sides  of  trees  and  stands,  susceptible  to 
the  injury  and  which  previously  have  been  densely  grown, 
should  when  possible  be  avoided. 

Snow  is  particularly  damaging  to  young  evenaged  densely 
stocked  stands  of  conifers.  It  can  be  minimized  by  the  sys- 
tematic use  of  thinnings  and  by  employing  the  selection 
method  in  elevated  regions  subject  to  heavy  snowfall. 

Losses  from  wind  can  be  reduced  by  starting  moderate, 
thinnings  early  and  repeating  often,  by  not  using  reproduc- 
tion methods  which  unduly  expose  a  portion  of  the  stand 
(Hke  the  seed  tree  method)  and  by  keeping  the  trees  healthy 


28o  PROTECTION  AGAINST  TREE  DISEASES 

and  sound,  thus  preventing  the  weakening  attacks  of  fungi. 
Under  intensive  management  shortening  of  the  rotation,  re- 
generation of  the  forest  in  directions  against  the  prevailing 
winds  and  the  development  of  protecting  strips  of  windfirm 
trees,  along  the  exposed  sides  of  stands  subject  to  wind  injury, 
will  assist  in  preventing  loss. 

Stagheadedness  can  be  prevented  by  maintaining  the  litter 
and  forest  canopy,  or  by  underplanting  if  the  canopy  is  thin 
or  broken. 

REFERENCES 

1.  Hartig,  Robert.  Lehrbuch  der  Baumkrankheiten.  2d  edition,  Ber- 
lin, 1889. 

2.  Hartig,  Robert.  Textbook  of  the  Diseases  of  Trees,  translated  by 
W.  SomerviUe  and  H.  Marshall  Ward,  London,  1894. 

3.  Rankin,  W.  H.     Manual  of  Tree  Diseases.     New  York,  1918. 

4.  Weir,  J.  R.  A  Study  of  the  Rots  of  Western  White  Pine.  Bulletin 
799,  U.  S.  Department  of  Agriculture,  Washington,  1919. 

5.  Meinecke,  E.  p.  Forest  Pathology  in  Forest  Regulation.  Bulletin 
27s,  U.  S.  Department  of  Agriculture,  Washington,  1915,  p.  12. 

6.  Long,  W.  H.  Investigations  of  the  Rotting  of  Slash  in  Arkansas. 
Bulletin  496,  U.  S.  Department  of  Agriculture,  Washington,  1917,  pp.  9-11. 

7.  Long,  W.  H.  A  New  Aspect  of  Brush  Disposal  in  Arizona  and  New 
Mexico.  Proceedings  of  the  Society  of  American  Foresters,  Vol.  10,  1915, 
PP-  383-398. 

8.  Weir,  J.  R.  and  Hubert,  E.  E.  Forest  Disease  Surveys.  Bulletin 
658,  U.  S.  Department  of  Agriculture,  Washington,  1918. 

9.  TuBEUF,  Karl  F.  von.  Diseases  of  Plants  induced  by  Cryptogamic 
Parasites,  London,  1897,  p.  83. 

10.  MiLLEN,  F.  H.  Disease  Control  and  Forest  Management.  Journal 
of  Forestry,  Vol.  XV,  191 7,  pp.  974-977. 

11.  Hubert,  E.  E.  Fungi  as  Contributory  Causes  of  Windfall  in  the 
Northwest.     Journal  of  Forestry,  Vol.  XVI,  1918,  pp.  696-714. 

12.  Weir,  J.  R.  and  Hubert,  E.  E.  The  Influence  of  Thinning  on  Western 
Hemlock  and  Grand  Fir  Infected  with  Echinodontium  Tinctorium.  Journal 
of  Forestry,  Vol.  XVII,  1919,  pp.  21-35. 

13.  Weir,  J.  R.  and  Hubert,  E.  E.  Pathological  Marking  Rules  for  Idaho 
and  Montana.     Journal  of  Forestry,  Vol.  XVII,  1919,     pp.  666-681. 

14.  Hubert,  E,  E.  The  Disposal  of  Infected  Slash  on  Timber-Sale  Areas 
in  the  Northwest.    Journal  of  Forestry,  Vol.  XVIII,  1920,  pp.  34-56. 


REFERENCES  281 

15.  Spaulding,  Perley.  The  Blister  Rust  of  White  Pine.  Bulletin  206, 
Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture,  Washington, 
1911. 

16.  Report  on  White  Pine  Blister  Rust  Control.  Bulletin  2,  American 
Plant  Pest  Committee,  Boston,  1918. 

17.  Detwiler,  S.  B.  White  Pine  Blister  Rust  Control  in  1919.  The 
American  Plant  Pest  Committee,  Boston,  1919. 

18.  ScHRENK,  H.  VON  and  Spaulding,  Perley.  Diseases  of  Deciduous 
Forest  Trees.  Bulletin  149,  Bureau  of  Plant  Industry,  U.  S.  Department  of 
Agriculture,  Washington,  1909. 

Anderson,  P.  J.  and  Babcock,  D.  C.     Field  Studies  on  the  Dissemination 

and  Growth  of  the  Chestnut  Blight  Fungus.     Bulletin  3,  Pennsylvania 

Chestnut  Tree  Blight  Commission,  Harrisburg,  1913. 
Anderson,  P.  J.  and  Rankin,  W.  H.     Endothia  Canker  of  Chestnut.     Bulle- 
tin 347,  New  York  State  Agricultural  Experiment  Station.     Ithaca,  19 14. 
Anderson,  P.  J.     The  Morphology  and  Life  History  of  the  Chestnut  Blight 

Fungus.     Bull.    7,    Pennsylvania    Chestnut    Tree    Blight    Commission, 

Harrisburg,  1914. 
BucKOUT,  W.  A.    The  Effect  of  Smoke  and  Gas  upon  Vegetation.    The 

Pennsylvania  State  College,  1902. 
Clevenger,  J.  F.     The  Effect  of  the  Soot  in  Smoke  on  Vegetation.     Smoke 

Investigation  Bulletin   7,  Mellon  Institute  of  Industrial  Research  and 

School  of  Specific  Industries,  Pittsburgh,  1913. 
Long,  W.  H.     Three  Undescribed  Heart-rots  of  Hardwood  Trees,  Especially 

of  Oak.     Journal  of  Agricultural  Research,  Vol.  i,  1913-14,  pp.  109-128. 
Long,  W.  H..  The  Death  of  Chestnuts  and  Oaks  due  to  ArmiUaria  Mellea. 

Bulletin  89,  U.  S.  Department  of  Agriculture,  Washington,  1914. 
Long,  W.  H.     A  preliminary  Report  on  the  Occurrence  of  Western  Red-rot 

in  Pinus   Ponderosa.     Bulletin  490,  U.   S.   Department  of  Agriculture, 

Washington,  191 7. 
Meinecke,  E.  p.     Forest  Tree  Diseases  common  in  California  and  Nevada. 

A  manual  for  Field  Use.     Forest  Service,  U.  S.  Department  of  Agriculture, 

Washington,  1914. 
Meinecke,  E.  P.    Basic  Problems  in  Forest  Pathology.    Journal  of  Forestry, 

Vol.  IS,  1917,  pp.  215-224. 
Metcalf,  Haven  and  Collins,  J.  F.    The  Present  Status  of  the  Chestnut 

Bark  Disease.     Bulletin  141,  Part  V,  Bureau  of  Plant  Industry,  U.  S. 

Department  of  Agriculture,  Washington,  1909. 
Metcalf,  H.  and  Collins,  J.  F.     The  Control  of  the  Chestnut  Bark  Disease. 

Farmers'  Bulletin  467,  U.  S.  Department  of  Agriculture,  Washington, 

1911. 


282  PROTECTION  AGAINST  TREE  DISEASES 

MiCKLEBOROUGH.  A  Report  on  the  Chestnut  Tree  Blight.  The  Fungus 
Diaporthe  Parasitica,  Murrill.  Department  of  Forestry,  Commonwealth 
of  Pennsylvania,  Harrisburg,  1909. 

Murrill,  W.  A.     Northern  Polypores,  New  York,  1914. 

Paul,  B.  H.  The  Pine  Blister.  Bulletin  15,  New  York  State  Conservation 
Commission,  Albany,  191 6. 

Final  Report  of  the  Pennsylvania  Chestnut  Tree  Blight  Commission.  January 
I  to  December  15,  1913.     Harrisburg,  1914. 

Reynolds,  H.  A.  A  Plan  to  Frustrate  the  White  Pine  Blister  Rust  in  Future 
Commercial  Plantings.  Bulletin  118,  Massachusetts  Forestry  Association, 
Boston,  1916. 

ScHRENK,  H.  VON.  Some  Diseases  of  New  England  Conifers.  Bulletin  25, 
U.  S.  Department  of  Agriculture,  Washington,  1900. 

ScHRENK,  H.  VON.  The  Diseases  of  the  Hardy  Catalpa.  Bulletin  37,  Bureau 
of  Forestry,  U.  S.  Department  of  Agriculture,  Washington,  1902. 

SCHRENK,  H.  VON.  A  Discase  of  the  White  Ash  Caused  by  Polyporus  Fraxi- 
nophilus.  Bulletin  32,  Bureau  of  Plant  Industry,  U.  S.  Department  of 
Agriculture,  Washington,  1903. 

SCHRENK,  H.  VON.  The  "Bluing"  and  the  "Red  Rot"  of  the  Western  Yellow 
Pine,  with  special  reference  to  the  Black  Hills  Forest  Reserve.  Bulletin  36, 
Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture,  Washington, 
1903. 

Shear,  C.  L.,  Stevens,  N.  E.  and  Tiller,  R.  J.  Endothia  parasitica  and 
related  species.  Bulletin  380,  U.  S.  Department  of  Agriculture,  Washing- 
ton, 1917. 

Spaulding,  Perley.  The  Present  Status  of  the  White-Pine  BHghts.  Circular 
35,  Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture,  Washing- 
ton, 1909. 

Spaulding,  Perley.  European  Currant  Rust  on  the  White  Pine  in  America. 
.  Circular  38,  Bureau  of  Plant  Industry,  U.  S.  Department  of  Agriculture, 
Washington,  1909. 

Spaulding,  Perley.  New  Facts  Concerning  the  White  Pine  Bhster  Rust. 
Bulletin  116,  U.  S.  Department  of  Agriculture,  Washington,  1914. 

Spaulding,  Perley.  The  White  Pine  Bhster  Rust.  Farmers'  Bulletin  742, 
U.  S.  Department  of  Agriculture,  Washington,  1916. 

Weir,  J.  R.  Observations  on  the  Pathology  of  the  Jack  Pine.  Bulletin  212, 
U.  S.  Department  of  Agriculture,  Washington,  1915. 

Weir,  J.  R.  Some  Factors  Governing  the  Trend  and  Practice  of  Forest  Sani- 
tation.    Forestry  Quarterly,  Vol.  13,  1915,  pp.  481-489. 

Weir,  J.  R.  Mistletoe  Injury  to  Conifers  in  the  Northwest.  Bulletin  360, 
U.  S.  Department  of  Agriculture,  Washington,  1916. 

Weir,  J.  R.  Larch  Mistletoe:  Some  Economic  Considerations  of  Its  Injurious 
Effects.     Bulletin  317,  U.  S.  Department  of  Agriculture,  Washington,  1916. 


REFERENCES  283 

Weir,  J.  R.  A  Needle  Blight  of  Douglas  Fir,  Journal  of  Agricultural  Re- 
search, Vol.  10,  Washington,  191 7,  pp.  99-104. 

Weir,  J.  R.  Effects  of  Mistletoe  on  Young  Conifers.  Journal  of  Agricultural 
Research,  Vol.  12,  Washington,  1918,  pp.  715-18. 

Weir,  J.  R.  and  Hubert,  E.  E.  A  Study  of  Heart-rot  in  Western  Hemlock, 
Bulletin  722,  U.  S.  Department  of  Agriculture,  Washington,  1918. 


CHAPTER  XVIII 

PROTECTION  AGAINST  DOMESTIC  ANIMALS; 
GRAZING 

Introductory.  —  The  common  domestic  animals  exerting 
direct  influence  upon  the  forest  are  cattle,  horses,  mules,  asses 
and  burros,  swine,  sheep  and  goats.  Poultry  may  also  be 
included  though  of  minor  importance. 

These  animals  are  distributed  through  all  parts  of  the 
United  States.^  Based  on  number  of  animals  the  region  from 
eastern  Nebraska  to  eastern  Ohio  and  from  the  southern  part 
of  the  Lake  States  to  St.  Louis  may  be  considered  the  center 
of  the  industry.  Sheep  furnish  an  exception  to  this  state- 
ment, about  40  per  cent  of  the  sheep  being  found  in  the  Rocky 
Mountain  States. 

The  use  of  forest  areas  for  grazing  purposes  is  of  common 
occurrence  throughout  the  country,  but  is  done  to  much 
greater  extent  in  some  parts  than  in  others.  The  entire  West, 
with  the  exception  of  those  few  sections  favored  with  abun- 
dant precipitation  and  mild  climate,  is  dependent  upon  for- 
ested grazing  lands  or  upon  elevated  areas  of  open  land,  so 
interspersed  among  forested  areas  as  to  require  management 
as  part  of  the  forest  property.  The  best  summer  forage  is  in 
or  adjacent  to  these  forested  areas.  The  same  land  must 
often  be  utilized  for  the  two  purposes  of  timber  production 
and  grazing. 

In  the  remainder  of  the  country,  wheredomestic  animals 
are  not  forced  to  take  refuge  in  the  forest  to  escape  unfavor- 
able climatic  conditions  and  where  density  of  forest  growth 
284 


THE   EFFECTS   OF   GRAZING  285 

largely  eliminates  forage,  the  use  of  the  forest  for  grazing 
purposes  on  a  large  scale  is  less  universal.  In  regions  such 
as  the  west  coast  of  Washington  and  Oregon,  with  climatic 
conditions  favorable  to  the  development  of  dense  forests, 
there  is  very  httle  forage  to  be  found  under  the  heavy 
forest  canopy. 

The  Effects  of  Grazing.  —  All  forests  are  not  equally  sus- 
ceptible to  injuries  from  grazing.  Hardwood  forests  are  more 
easily  injured  by  browsing  but  recover  better  than  do  conifers. 
Due  to  the  fact  that  the  animals  prefer  to  browse  upon  hard- 
woods, grazing  usually  favors  conifers  as  contrasted  to  hard- 
woods in  mixed  stands. 

Shallow  rooted  species  are  likely  to  receive  more  injury 
through  trampling  than  deep  rooted  trees. 

The  effects  of  grazing  may  be  subdivided  into : 

Effect  upon  the  soil. 

Effect  upon  reproduction. 

Effect  upon  trees  past  the  reproduction  stage. 

Effect  upon  the  control  and  prevention  of  forest  fires. 

Efect  Upon  the  Soil.  —  The  physical  condition  of  the  soil 
is  injured  by  the  trampling  of  the  animals  which  compacts 
and  hardens  the  soil.  Erosion  is  often  started  on  steep  slopes 
and  on  other  lands  where  the  ground  cover  is  closely  browsed 
or  destroyed.  Trampling,  particularly  by  animals  with  sharp 
hoofs,  has  a  loosening  and  cutting  effect  upon  the  surface  of 
the  soil  which  may  be  washed  away  in  succeeding  rains. 
Grazing  as  a  cause  of  erosion  is  of  great  importance  in  the 
western  half  of  the  United  States,  as  indicated  by  the  follow- 
ing quotation  from  Sampson  and  Weyl-:  "Serious  erosion  on 
western  range  lands  is  due  chiefly  to  the  destruction  of  the 
vegetation  as  a  result  of  overgrazing  and  mismanagement  of- 
live  stock." 


286       PROTECTION  AGAINST  DOMESTIC  ANIMALS;   GRAZING 

Sheep  with  their  short  tread  and  sharp  feet  are  particularly- 
injurious  to  the  soil. 

Efect  Upon  Reproduction. — The  branches  and  terminal 
shoots  of  seedlings  suffer  from  browsing.  As  a  result  they 
are  deformed  and  lose  increment.  Sometimes  seedlings  are 
killed.  If  not  killed  the  seedKngs  eventually  may  grow  in 
height  until  their  crowns  are  above  the  reach  of  animals.  In 
such  cases  the  deformities  received  in  early  youth  are  out- 
grown by  the  time  the  tree  is  ready  for  cutting.^ 

Hogs  eat  the  seeds  of  certain  species  such  as  the  oaks,  and 
in  the  case  of  the  long  leaf  pine,  uproot  and  devour  the  roots. 
Indeed  hogs  are  a  primary  factor  in  preventing  longleaf  pine 
reproduction.'^ 

Many  seedKngs  are  injured  by  being  trampled  upon,  and  by 
having  their  roots  exposed  and  barked. 

Sometimes  bark  is  gnawed  or  peeled  from  seedlings.  Goats 
in  particular  perform  this  type  of  injury.  They  are  consid- 
ered the  most  destructive  to  reproduction  of  all  the  domestic 
animals. 

In  addition  to  injuring  or  destroying  existing  reproduction, 
animals  through  their  effect  on  the  soil  may  create  seedbed 
conditions  unfavorable  for  the  start  of  reproduction.  Their 
influence  upon  the  seedbed  may  be  beneficial,  especially  that 
of  hogs.  The  latter  in  their  search  for  food  mix  the  litter  and 
soil  and  may  expose  the  mineral  soil. 

Where  in  a  mixed  stand,  species  with  palatable  seeds  are 
less  desirable  in  management  than  others  with  inedible  seeds 
and  preference  for  a  mineral  seedbed,  hogs  may  be  of  distinct 
benefit.  Shortleaf  pine  in  mixtures  of  oak  is  favored  by  the 
grazing  of  hogs  for  this  reason. 

The  loss  of  all  or  a  portion  of  the  reproduction  may  result 
in  inadequate  density  of  stocking,  which  in  turn  means  lower 
increment  or  reduced  quality  of  product. 


BENEFITS   VERSUS   INJURIES   FROM   GRAZING  287 

Efect  Upon  Trees  Past  the  Reproduction  Stage.  —  When 
trees  have  once  elevated  their  crowns  above  the  reach  of 
animals  they  are  free  from  serious  direct  injury  by  domestic 
animals.  There  may  be  some  injury  done  by  trampling  and 
barking  exposed  roots  or  by  rubbing  (principally  due  to  cattle) 
and  by  the  compacting  of  the  soil  so  as  to  hinder  aeration. 
The  chief  loss  is  a  reduction  of  the  increment  of  the  stand 
resulting  from  the  injurious  effects  of  grazing  upon  soil. 

Effect  Upon  the  Control  and  Prevention  of  Forest  Fires.  — 
Grazing  has  a  distinctly  beneficial  influence  upon  the  forest 
fire  problem.^  Grasses  and  forage  plants  when  present  in  the 
forest  constitute  the  most  readily  inflammable  portion  of  the 
fuel  for  fires.  When  this  is  removed  by  grazing  the  fire  hazard 
is  reduced,  the  start  of  a  fire  being  rendered  less  easy  and  in 
some  cases  its  rapid  spread  made  impossible.  The  beneficial 
influence  of  grazing  upon  fire  protection  may  offset  all  injury 
caused  to  the  soil  and  the  forest. 

In  the  past  the  idea  has  prevailed  in  certain  sections  of  the 
country  that  annual  fires  set  in  the  late  winter  or  early  spring 
to  keep  down  brush  and  to  burn  off  the  dead  herbage,  thus 
permitting  the  stock  to  reach  the  tender  new  shoots,  were  of 
benefit  to  the  grazing  industry.^  The  fallacy  of  this  theory 
has  been  exposed  and  it  is  now  recognized  that  a  decrease  of 
the  better  and  an  increase  of  the  inferior  varieties  of  forage 
plants  is  a  consequence  of  annual  burning. 

In  the  past  stockmen  have  been  responsible  for  setting 
many  fires  intentionally  with  the  mistaken  idea  of  improving 
the  grazing,  to  keep  down  the  brush  and  in  the  South  to 
destroy  the  cattle  tick.  The  situation  is  steadily  improving 
and  within  a  relatively  short  period  any  injurious  influence  of 
grazing  upon  the  control  and  prevention  of  fires  will  be  a 
thing  of  the  past. 

Benefits  versus  Injuries  from  Grazing.  —  The  extent  of  the 


288       PROTECTION  AGAINST  DOMESTIC  ANIMALS;   GRAZING 

injury  to  the  production  of  tree  crops  is  exceedingly  difficult 
to  estimate,  since  the  major  portion  of  the  loss  accrues  to  young 
reproduction  and  to  soil  conditions.  So  far  as  is  known  no 
general  estimates  of  the  damage  have  been  madeJ 

Grazing  is  beneficial  to  the  community  as  a  whole  producing 
enormous  annual  receipts  expressed  either  as  rents  for  grazing 
privileges  or  values  of  domestic  animals  supported. 

Damage  to  the  forest  often  is  considered  incidental  and  a 
necessary  consequence  of  the  grazing  industry.  On  the  other 
hand,  there  are  many  areas  where  the  forest  must  be  consid- 
ered first  and  only  such  an  amount  of  grazing  allowed  as 
will  not  injure  the  forests  or  alter  their  influence.  The 
National  Forests  fall  within  this  class  of  land  and  require 
such  management  of  the  grazing  as  shall  not  interfere  with 
the  primary  purposes  of  timber  production  and  watershed 
protection.^ 

Too  little  consideration  has  been  given  the  question  of 
relative  benefits,  likely  to  follow  from  the  use  of  given  areas 
of  land  for  production  of  trees  or  for  grazing  purposes,  and 
the  extent  to  which  the  two  can  be  combined  profitably  upon 
the  same  areas.  Until  this  information  is  secured,  it  may  be 
difficult  to  determine  whether  certain  of  the  harmful  effects 
of  grazing  upon  the  forest  should  be  tolerated  or  prevented. 

Woodward,  who  is  working  on  the  problem  of  the  relative 
profits  from  grazing  and  tree  crops,  intimates,  in  a  letter  to  the 
author,  that  for  southern  New  Hampshire  the  net  annual 
returns  per  acre  from  grazing  are  less  than  can  be  secured  in 
growing  white  pine  on  the  same  land. 

Secrest^  states,  with  reference  to  conditions  in  Ohio,  that 
the  value  of  the  average  woodland  pasture  is  not  over  fifty 
cents  per  acre  per  year.  Higher  returns  than  this  should  be 
secured  through  tree  crops. 

Methods  of  Control  and  Prevention.  —  Methods   of  con- 


METHODS  OF  CONTROL  AND  PREVENTION      289 

trolling  and  preventing  injury  from  grazing  may  be  sum- 
marized under  the  following  two  headings: 

Protection  by  excluding  domestic  animals  from  the  area  to 
be  protected. 

Protection  by  close  regulation  of  the  grazing  in  the  area  to 
be  protected. 

Protection  by  Excluding  Domestic  A  nimals.  —  Domestic 
animals  may  be  excluded  from  an  area  throughout  the  entire 
rotation  or  only  for  the  regeneration  period.  Exclusion  for 
the  entire  rotation  might  be  necessary  in  protection  forests, 
where  serious  damage  from  erosion  might  occur  or  the  Hfe  of 
the  forest  be  threatened.  Elsewhere  such  an  extreme  meas- 
ure rarely  is  justified.  Exceptions  will  be  found  in  forests 
where  grazing  is  exceedingly  injurious.  In  such  forests  it  may 
be  necessary  permanently  to  exclude  stock,  even  though  the 
forests  be  managed  primarily  for  timber  production  rather 
than  for  protection  purposes. 

Most  of  the  direct  damage  to  the  forest  is  done  during  the 
reproduction  period.  Hence  keeping  out  animals  at  that 
time  will  often  reduce  the  total  injury  to  an  insignificant 
amount.  Barnes^",  page  212,  of  his  book  "Western  Grazing 
Grounds  and  Forest  Ranges,"  in  discussing  injury  by  sheep 
to  areas  being  reproduced  says:  "Such  areas  can  therefore  be 
temporarily  closed,  and  once  the  young  timber  is  past  the 
danger  stage  can  be  again  opened  for  grazing." 

Selection  stands  are  continually  undergoing  regeneration 
and  in  need  of  constant  protection  from  grazing. 

Protection  by  Close  Regulation  of  the  Grazing.  —  This 
method  is  in  successful  operation  over  a  large  part  of  the 
National  Forests.  The  following  quotation  from  Western 
Grazing  Grounds  and  Forest  Ranges,  page  209,  by  Barnes, ^° 
indicates  the  situation:  "There  are  few  of  the  national  forests 
which  to-day  are  not  open  to  grazing  of  some  kind  of  stock  in 


290       PROTECTION  AGAINST  DOMESTIC  ANIMALS;   GRAZING 

every  part,  although  on  some  of  them  it  has  been  considered 
advisable  to  close  certain  areas  to  grazing  of  all  kinds." 
Grazing  is  allowed,  but  the  numbers,  season  for  grazing, 
methods  of  handling  the  animals,  etc.,  are  carefully  regulated. 

Experience  in  the  western  United  States  has  demonstrated, 
that  the  injurious  effects  of  grazing  increase  rapidly  with  the 
number  of  head  of  stock  grazed  on  a  given  area.  If  over- 
grazing is  avoided,  the  damage  to  the  average  forest  and  soil 
is  so  small  as  often  to  be  safely  disregarded.  Until  forage 
becomes  scarce,  the  animals  do  not  browse  the  less  palatable 
food  furnished  by  trees.  By  properly  regulating  the  number 
of  animals  sufficient  forage  is  provided  for  all  animals.. 

Sometimes  the  slash  can  be  disposed  of  in  such  a  manner  " 
around  stumps  or  groups  of  reproduction  as  to  protect  the 
young  trees  from  the  animals. 

Outside  of  the  national  forests  little  if  anything  has  been 
done  to  regulate  grazing  in  forested  areas.  There  is  a  large 
field  for  its  application  on  tracts  of  all  sizes  from  the  smallest 
woodlot  upward. 

The  general  trend  of  the  live  stock  industry  over  the  whole 
country  is  toward  more  intensive  methods  of  handling.  As 
this  affects  the  forest,  it  means  a  restriction  of  the  general 
running  of  live  stock  over  wild  wooded  areas  and  the  increase 
of  feeding  in  buildings  and  well  kept  pastures.  In  parts  of 
the  West  where  the  national  forest  lands  furnish  the  requisite 
summer  forage,  the  use  of  forested  lands  as  grazing  grounds 
will  continue  indefinitely  on  a  large  scale.  Elsewhere  the 
setting  aside  of  separate  areas  for  forest  use  and  for  pasturage 
purposes  is  hkely  to  find  increasing  favor. 


REFERENCES  291 


REFERENCES 

1.  Thirteenth  Census  of  the  United  States  taken  in  the  Year  1910.  Bureau 
of  the  Census,  Department  of  Commerce,  Vol.  V,  Washington,  1913,  pp. 
327-472. 

2.  Sampson,  A.  W.,  and  Weyl,  L.  H.  Range  Preservation  and  Its  Rela- 
tion to  Erosion  Control  on  Western  Grazing  Lands.  Bulletin  675,  U.  S. 
Department  of  Agriculture,  Washington,  1918,  p.  35. 

3.  Hill,  R.  R.  Effects  of  Grazing  upon  Western  Yellow-Pine  Reproduc- 
tion in  the  National  Forests  of  Arizona  and  New  Mexico.  Bulletin  580,  U.  S. 
Department  of  Agriculture,  Washington,  191 7,  p.  20. 

4.  Hardtner,  H.  E.  a  Practical  Example  of  Forest  Management  in 
Southern  YeUow  Pine.  Proceedings  of  the  Southern  Forestry  Congress, 
Chapel  Hill,  1916,  pp.  71-80. 

5.  Mason,  D.  T.  Brush  Disposal  in  Lodgepole-pine  Cuttings.  Proceed- 
ings of  the  Society  of  American  Foresters,  Vol.  10,  191 5,  pp.  399-404. 

6.  Cary,  a.  Ticks  and  Timber.  American  Forestry,  Vol.  26,  1920,  pp. 
92-94. 

7.  Sparhawk,  W.  N.  Effect  of  Grazing  upon  Western  Yellow  Pine  Re- 
production in  Central  Idaho.  Bulletin  738,  U.  S.  Department  of  Agriculture, 
Washington,  1918,  pp.  22-25. 

8.  Jardine,  J.  T.,  and  Anderson,  M.  Range  Management  on  the 
National  Forests.  Bulletin  790,  U.  S.  Department  of  Agriculture,  Washing- 
ton, 1919. 

9.  Secrest,  E.  The  Role  of  Artificial  Regeneration  in  the  Re-enforce- 
ment of  Hardwood  Woodlots.     Journal  of  Forestry,  Vol.  XVI,  1918,  p.  329. 

10.  Barnes,  W.  C.     Western  Grazing  Grounds  and  Forest  Ranges,  Chicago, 

1913- 

11.  Sampson,  Arthur  W.  Effect  of  Grazing  upon  Aspen  Reproduction. 
Bulletin  741,  U.  S.  Department  of  Agriculture,  Washington,  1919. 

Chapline,  W.  R.  Production  of  Goats  on  Far  Western  Ranges.  Bulletin 
749,  United  States  Department  of  Agriculture,  Washington,  1919. 

Coville,  F.  V.  Forest  Growth  and  Sheep  Grazing.  Bulletin  15,  Division  of 
Forestry,  United  States  Department  of  Agriculture,  Washington,  1898. 

DuBois,  C.  Systematic  Fire  Protection  in  the  California  Forests.  Forest 
Service,  United  States  Department  of  Agriculture,  Washington,  1914,  p.  89. 

Hatton,  J.  H.  Live-Stock  Grazing  as  a  Factor  in  Fire  Protection  on  the 
National  Forests.  Circular  134,  United  States  Department  of  Agriculture, 
Washington,  1920. 

HODSON,  E.  R.  The  Effect  of  Grazing  on  the  Caribou  National  Forest.  For- 
estry Quarterly,  Vol.  8,  1910,  pp.  158-168. 


292       PROTECTION  AGAINST  DOMESTIC  ANIMALS;   GRAZING 

Ivy,  T.  p.     Forestry,  Livestock  and  Cut-over  Lands  of  the  South.     American 

Forestry,  Vol.  26,  1920,  pp.  299-302. 
Jardine,  J.  T.     Efficient  Regulation  of  Grazing  in  Relation  to  Timber  Produc- 
tion.    Journal  of  Forestry,  Vol.  18,  1920,  pp.  367-382. 
Reynolds,   R.   V.   R.     Grazing   and   Floods.     Bulletin   91,    Forest   Service, 

United  States  Department  of  Agriculture,  Washington,  191 1. 
Roth,  F.     Grazing  in  the  Forest  Reserves.     Yearbook,  of  the  United  States 

Department  of  Agriculture  for  1901,  Washington,  1902,  pp.  333-348. 
The  Use  Book.     Forest  Service,  United  States  Department  of  Agriculture, 

Washington,  1918,  p.  76. 
TiLLOTSON,  C.  R.     The  Care  and  Development  of  the  Woodlot.     Farmers' 

Bulletin  711,  United  States  Department  of  Agriculture,  Washington,  1916, 

pp.  13-16. 


CHAPTER  XIX 

PROTECTION    AGAINST     ANIMALS  —  OTHER    THAN 
INSECTS   AND   DOMESTIC   ANIMALS 

The  principal  animals,  not  previously  considered,  causing 
damage  to  tree  crops  include  deer,  beaver,  porcupines,  rab- 
bits, mice,  squirrels  and  birds.  Injuries  resulting  from  the 
work  of  these  animals  are  less  extensive  in  the  aggregate  than 
those  produced  by  any  of  the  four  injurious  agencies  described 
in  the  preceding  chapters.  However,  in  individual  cases,  rela- 
tively large  losses  may  ensue  from  the  attacks  of  any  one  of 
these  animals. 

Deer.  —  Deer  cause  injuries  of  the  same  type  as  those 
produced  by  domestic  animals.  The  numbers  of  deer  are 
ordinarily  too  small  to  effect  serious  damage  except  on  occa- 
sional, scattered  trees.  Other  than  by  restricting  the  num- 
ber of  deer  in  a  forest  through  shooting  them,  injury  by  deer 
cannot  under  present  economic  conditions  be  prevented. 

Beaver.  —  Beaver  by  girdling  and  felling  trees,  often  of 
merchantable  size,  kill  a  good  many  trees  in  the  vicinity  of 
their  ponds  and  dams.  Certain  species,  particularly  the 
aspens,  are  preferred  and  the  beaver  will  go  a  considerable 
distance  to  find  the  favored  species  if  not  available  close  at 
hand.  They  may  destroy  the  entire  stand  adjacent  to  their 
ponds  by  raising  the  water  level  thus  submerging  the  root 
systems  of  standing  trees  or  at  least  increasing  the  moisture 
content  of  the  soil.  Beaver  are  relatively  scarce  and  in  only 
a  few  regions  are  they  a  nuisance. 

Porcupines.  —  Damage    by    porcupines    consists    in    the 
gnawing  of  bark  on  standing  trees.     The  injury  may  occur 
293 


294  PROTECTION  AGAINST  ANIMALS 

on  any  part  of  the  stem  or  on  the  branches  as  the  animals 
climb  the  trees.  When  gnawed  completely  around  that  por- 
tion of  the  tree  above  the  injury  dies. 

KiUing  the  porcupines  is  the  best  remedy.  A  bounty  placed 
on  the  animals  will  stimulate  reduction  in  their  numbers. 

Rabbits.  —  Gnawing  of  the  bark  in  winter,  often  causing 
the  girdling  and  death  of  the  tree,  is  done  by  rabbits.  Seed- 
lings and  small  trees  are  cliiefiy  affected.  Hardwoods  are 
preferred  rather  than  coniferous  species.  Rabbits  are  some- 
times so  numerous  and  so  destructive  as  to  prevent  repro- 
duction. In  such  a  case  virtual  extermination  may  be  neces- 
sary to  control  the  pests. 

Squirrels.  —  Squirrels  eat  seeds  and  fruits  and  bite  off 
young  shoots  and  buds.  In  many  instances  they  devour 
practically  all  of  the  seed  crop  of  given  species.  Conse- 
quently squirrels  are  often  an  important  factor  in  the  securing 
of  natural  reproduction. 

Shooting  of  squirrels  should  be  encouraged  as  the  most 
practicable  method  of  protection. 

Mice.  —  Seeds  are  devoured  by  mice,  which  are  particu- 
larly to  be  feared  in  nursery  seedbeds.  Mice,  during  the 
winter  when  food  is  scarce,  gnaw  the  bark  of  seedhngs  and 
young  trees  either  above  or  below  ground,  often  girdling  them 
and  causing  death.  The  mice  are  most  abundant  on  grass 
covered  areas  with  sunny  aspect.  Periodically  the  mice  are 
likely  to  increase  and  girdle  a  large  proportion  of  the  trees  on 
restricted  areas.  In  nurseries  intensive  methods  of  combat- 
ing mice  are  warranted  and  can  be  successfully  apphed.  In 
the  forest  poisoning  may  be  justified  when  the  mice  are 
abundant,  and  the  injury  concentrated. 

Birds.  —  The  beneficial  influence  of  birds  in  destroying 
insect  enemies  outweighs  their  injurious  effects  upon  the 
forest.     Birds  feed  upon  the  seeds  of  forest  trees,  bite  off  the 


REFERENCES  295 

tops  of  seedlings  and  in  the  case  of  woodpeckers  peck  holes 
in  the  trees.  On  the  whole  birds  should  be  protected  and 
encouraged  to  increase  in  the  forest.  The  injury  to  seeds 
and  seedHngs  is  most  noticeable  in  nurseries  where  it  can  be 
successfully  prevented  by  protecting  the  seed  beds  with  wire 
netting. 

REFERENCES 

Fisher,  W.  R.     Forest  Protection.     Schlich's  Manual  of  Forestry,  Vol.  IV, 

London,  1895,  pp.  84-131. 
Lautz,  D.  E.     Cottontail  Rabbits  in  Relation  to  Trees  and  Farm  Crops. 

Farmers'  Bulletin  702,  U.  S.  Department  of  Agriculture,  Washington,  1916. 
Laxjtz,  D.  E.     Field  Mice  as  Farm  and  Orchard  Pests.     Farmers'  Bulletin  670, 

U.  S.  Department  of  Agriculture,  Washington,  1915. 
Dearborn,  N.     Seeding-eating  Mammals  in  Relation  to  Reforestation.     Cir- 
cular 78,  Bureau  of  Biological  Survey,  U.  S.  Department  of  Agriculture, 

Washington,  191 1. 
Berry,  S.    Work  of  California  Gray  Squirrel  on  Conifer  Seed  in  the  Southern 

Sierras.     Proceedings  of  the  Society  of  American  Foresters,  Vol.  9,  1914, 

pp.  95-97. 
Jotter,    E.     Squirrels   and    Sugar-pine    Reproduction.     Proceedings   of  the 

Society  of  American  Foresters,  Vol.  9,  1914,  pp.  98-101. 
Miller,  J.  M.     Cone  Borer  versus  Squirrel.     Forestry  Quarterly,  Vol.  12, 

1914,  pp.  238-239. 
IVIcAtee,  W.  L.     Woodpeckers  in  Relation  to  Trees  and  Wood  Products. 

Bulletin  39,  Biological  Survey,  U.  S.  Department  of  Agriculture,  Wash- 
ington, 191 1. 
Phtllips,  F.  J.     The  Dissemination  of  Junipers  by  Birds.     Forestry  Quarterly, 

Vol.  8,  pp.  60-73. 
Sterling,  E.  A.     Adirondack  Birds  in  Their  Relation  to  Forestry.     Forestry 

Quarterly,  Vol.  i,  pp.  18-25. 


CHAPTER  XX 

PROTECTION  AGAINST  AVALANCHES,  LAND-SLIDES, 
FLOODS   AND   SHIFTING   SAND 

Avalanches.  —  The  forest  needs  protection  against  injury 
from  avalanches  or  snow-slides  and  is  itself  a  protective  agent 
in  preventing  damage  from  avalanches  to  property  outside  the 
forest. 

Injury  from  avalanches  is  a  possibility  over  a  small  frac- 
tion of  the  forest  area,  situated  on  steep  mountain  slopes  in 
regions  of  heavy  snowfall  and  usually  adjacent  to  timberline. 

Avalanches  when  once  started  may  break  down  and  thus 
destroy  the  forest  in  their  path.  They  do  not  start  within 
the  properly  managed  forest  but  originate  above  timberline 
and  on  cutover  or  burned  areas.  Long  grass,  ground  cover, 
brush  and  reproduction  assist  in  preventing  the  start  of 
avalanches.  Once  started  avalanches  are  difhcult  to  stop, 
hence  protective  measures  should  be  directed  toward  pre- 
venting their  origin. 

Above  timberline  protective  measures  include  the  encour- 
agement of  all  woody  plant  vegetation,  the  preservation  of  a 
grass  sod  and  at  the  most  dangerous  points  the  construction 
of  ditches,  walls  and  fences. 

Below  timberline  protective  measures  require  the  main- 
tenance of  a  protection  forest.  Hunger  ^  mentions  four 
requirements  for  treatment  of  such  a  forest. 

I.  Complete  fire  protection.  This  encourages  the  de- 
velopment of  ground  cover,  underbrush  and  repro- 
duction. 

296 


FLOODS  297 

2.  Exclusion  of  grazing  with  the  same  object  in  view  of 

keeping  the  soil  densely  covered. 

3.  Careful   cutting   of   timber  on   steep   slopes  with  a 

gradient  exceeding  50  per  cent.  Single  tree  selec- 
tion is  the  proper  method  of  reproduction  to  use. 
Clearcutting  should  be  prohibited. 

4.  Prompt  reforestation  of  denuded  areas,  in  order  to 

reestablish  forest  conditions. 

Land-slides.  — Land-slides  occur  through  the  action  of  water 
in  the  subsoil  or  on  the  surface  on  steep  slopes,  particularly 
when  an  impermeable  layer  of  rock  or  soil  prevents  the 
further  entrance  of  the  water  into  the  ground.  They  carry 
down  the  soil  and  the  forest  leaving  a  bare  exposed  slope. 
Injury  from  land-sHdes  may  be  expected  in  mountainous 
regions  of  abundant  precipitation. 

The  same  protective  measures  appUcable  in  the  forest 
against  avalanches  should  be  employed  to  prevent  the  start  of 
land-slides. 

Floods.  —  The  influence  of  floods  within  the  forest  is  both 
harmful  and  beneficial.  Damage  is  done  by  destroying  young 
plants,  wounding  larger  trees  through  the  action  of  ice  and 
floating  debris  and  gull>dng  and  carrying  away  the  fertile  soil. 
Deposits  of  rich  silt  may  be  spread  periodically  over  the 
ground  which  greatly  increases  the  productivity  of  the  site 
and  is  distinctly  beneficial. 

On  forest  lands  subject  to  floods  species  capable  of  with- 
standing inundation  should  be  grown.  Pollarding  which  keeps 
the  young  shoots  above  the  floods  is  a  suitable  method  of 
treatment.  Selection  and  coppice  with  standards  under  both 
of  which  methods  part  of  the  stand  always  remains  on  the 
area  are  better  suited  to  the  conditions  than  other  reproduc- 
tion methods. 

A  complete  forest  cover  assists  in  preventing  floods,  but 


298  PROTECTION  AGAINST  AVALANCHES,  ETC. 

special  measures  are  required  to  adequately  control  floods. 
Consideration  of  this  subject  is  outside  the  scope  of  the  present 
work. 

Shifting  Sands.  —  Shifting  sands  are  capable  of  destroying 
entire  forests,  and  conversely  the  estabhshment  and  main- 
tenance of  forests  upon  areas  of  shifting  sands  is  the  only 
method  of  rendering  them  productive  and  preventing  injury 
to  adjacent  property. 

The  reclamation  of  shifting  sands  is  not  here  pertinent. 
The  important  point  in  the  prevention  of  injury  to  estab- 
lished forests  from  shifting  sands  is  to  preserve  intact  the 
humus,  litter,  and  ground  cover  and  thereby  afford  no  oppor- 
tunity for  the  sand  to  move. 

Grazing  should  be  excluded  or  closely  regulated  to  prevent 
over-grazing.  The  selection  method  is  preferable,  though  if 
the  forest  floor  is  unbroken  and  reproduction  starts  promptly 
other  reproduction  methods  are  allowable. 

REFERENCES 

I.  MuNGER,  T.  T.  Avalanches  and  Forest  Cover  in  the  Northern  Cascades. 
Circular  173,  U.  S.  Department  of  Agriculture,  Washington,  191 1. 

Fisher  W.  R.     Forest  Protection.      Schlich's  Manual  of  Forestry,  Vol.  IV, 
London,  1895,  pp.  496-538. 


APPENDIX 


FOREST  TERMINOLOGY* 

Terms  in  Forestry 

COMPILED  BY   A  COMMITTEE   OF   THE   SOCIETY   OF   AMERICAN  FORESTERS 

Absolute  forest  land.     Land  fit  only  for  forest  growth. 

Syn. :  absolute  forest  soil.     G.,  Absoluter  Waldboden.     F.,  sol  forestier. 
Absolute  form  factor.     See  Form  factor. 
Acid  humus.     See  Humus. 
Accretion.     See  Increment. 

Advance  growth.  Young  trees  which  have  sprung  up  spontaneously  in 
openings  in  the  forest,  or  under  the  forest  cover  (before  reproduction 
fellings  are  begun). 

Syn. :  volunteer  growth. 
G.,  Vorwuchs.     F.,  semis  preexistant. 
Afforestation.     See  Forestation. 

Age  class.  All  trees  in  a  stand  or  forest  whose  age  falls  within  stated 
Umits,  usually  divided  in  20-year  periods  (5  years  in  coppice),  but  in 
old  stands  may  be  of  wider  range,  and  may  be  stated  in  extent  of  area 
or  in  percentage  of  the  whole  stand  or  forest,  or,  in  selection  forest,  by 
number  of  trees.  A  stand  in  which  the  trees  fall  between  the  age  of 
I  to  20  years  would  be  referred  to  as  age  class  I.  See  also  Develop- 
ment class. 

G.,  Altersklasse.     F.,  classe  d'age. 

Gradation  of  age  classes  refers  more  specifically  to  this  formation  of 
age  classes.     See  also  Tree  class. 

G.,  Altersabstufung.     F.,  gradation  d'age. 

Distribution  of  age  classes  refers  to  either  the  local  distribution  of  age 
classes  (G.,  Verteilung  der  Altersklassen,  Altersklassenlagerung) ;    or 

*  Reprinted  from  the  Journal  of  Forestry  Vol.  XV,  191 7,  pp.  71-ioi. 
299 


300  APPENDIX 

to  the  percentic  or  absolute  representation  of  the  different  age  classes 
in  area  or  amount,  or  (in  selection  forest)  in  number  of  trees  (G., 
Altersklassenverhaltniss) . 

Disruption  of  age  classes  refers  to  the  attempt  to  provide  safety 
against  fire  or  insects,  by  locating  the  age  classes  in  small  areas. 
G.,  Altersklassenzerreissung. 
Normal  age  classes.     See  Normal. 

All-aged  forest.     (Obs.)     See  Uneven-aged  forest,  Selection  forest. 

Annual  plans.     See  Working  plan. 

Area  tape.  A  tape  from  which  the  basal  area  may  be  read  directly  when 
it  is  placed  around  the  tree. 

Artificial  reproduction.     See  Reproduction. 

Aspect.     The  direction  toward  which  a  slope  faces.     The  eight  main 
points  of  the  compass,  N.,  NE.,  E.,  SE.,  S.,  SW.,  W.,  NW.,  are  distin- 
guished in  forest  description. 
Syn.:  exposure. 
G.,  Lage.     F.,  exposition. 

Assortment.  The  classes  of  wood  materials  into  which  the  harvested 
crop  may  be  divided,  as  logs,  fuel  wood,  pulpwood,  railway  ties,  etc., 
or  according  to  size  into  timberwood  (stoutwood,  above  3-inch  diam- 
eter) ;  brushwood  (below  3-inch  diameter) ;  cordwood,  split  and  billets, 
etc.     See  also  Grading. 

G.,  Sortiment.     F.,  categorie. 

Ball  planting.     See  Forest  planting. 

Bark  blazer  or  gouger.     See  Scribe. 

Barren.  An  area  which  is  devoid  of  trees  (moss  barren),  or  bearing  only 
stunted  trees,  then  denoted  by  the  character  of  the  tree  growth,  as 
pine  barren,  oak  barren,  spruce  barren. 

Basal  area.    The  area  of  a  cross  section  of  a  tree,  usually  expressed  in 
square  feet,  and  usually  referring  to  the  section  at  breast-height.     The 
sum  of  the  basal  areas  of  trees  in  a  stand  is  the  basal  area  of  the  stand, 
and  is  usually  expressed  in  square  feet  per  acre. 
G.,  Stammgrundflache.     F.,  surface  terriere. 

Base  capital.     See  Capital. 

Biltmore  stick.  A  graduated  rule,  usually  of  wood,  the  graduations  of 
which  indicate  (when  the  rule  is  held  tangentially  to  the  tree)  the 
diameter  of  the  tree  at  the  point  where  measured.  The  rule  is  con- 
structed on  the  principle  of  similar  triangles.     See  also  Caliper. 


APPENDIX  301 

Blank.    An  opening  in  the  forest  where,  from  any  cause,  very  few  or  no 
trees  are  growing. 
G.,  Blosse.     F.,  yide. 

Blaze,  V.  The  process  of  marking  a  tree  by  means  of  a  sharp  instrument, 
removing  part  of  the  bark. 

Blaze,  n.     A  spot  made  on  a  tree  by  chipping  off  a  piece  of  bark. 

Block.     See  Under  subdivision. 

Blow-down.     See  Windfall. 

Board  foot.  A  unit  of  measurement  represented  by  a  board  one  foot 
long,  one  foot  wide  and  one  inch  in  thickness,  or  its  equivalent  in 
volume.  In  finished  or  surfaced  lumber  the  board  foot  measure  is 
based  on  the  measurement  before  surfacing  or  other  finishing,  or  on 
the  superficial  measure  only. 

Board  measure.  A  term  expressing  the  board  foot  content  of  roimd  or 
manufactured  timber;  and  for  expressing  the  volume  of  logs,  trees  or 
stands  in  terms  of  the  estimated  amount  of  lumber  which  may  be  cut 
therefrom  according  to  various  log  rules  (g.  v.).  Usually  abbreviated 
B.M.;  units  of  larger  quantities  stated  in  thousands,  are  abbreviated 
M.  B.  M. 

Board  rule.  1.  A  tabular  statement  showing  the  board  foot  contents 
for  various  widths  and  lengths  of  squared  timber,  or  of  sawed 
timber. 

2.   A  graduated  stick  for  determining  the  contents  of  squared  timber. 
The  number  of  board  feet  in  squared  timber  of  given  widths  and  lengths, 
or  of  sawed  timber,  is  shown  upon  the  rule.    See  Scale  stick. 
Syn.:  lumber  rule,  lumber  scale. 

Board  scale.    See  Board  measure. 

Bole.     See  Stem. 

Border  cutting.     See  Reproduction,  Strip-selection  method. 

Breast-height.     A  height  of  4^  feet  above  the  average  ground  surface  or 
above  the  root  collar,  the  diameters  of  standing  trees  being  ordinarily 
measured  at  this  height  (abbreviation  d.  b.  h.). 
G.,  Brusthohe.     F.,  hauteur  d'homme. 

Breast-height  form  factor.     See  Form  factor. 

Broadcast  seeding  method.     See  Direct  seeding. 

Broken.     See  Crown  density. 

Brushwood  stage.     See  Development  class. 

Budget  regulation.    See  Regulation  of  cut. 


302  APPENDIX 

Bunch  planting.     See  Forest  planting. 

Burn,  n.     An  area  over  which  fire  has  run  to  the  noticeable  injury  of  the 

forest. 
Caliper,  n.     An  instrument  for  measuring  diameter  of  trees  or  logs.     It 
consists  usually  of  a  graduated  beam,  at  right  angles  to  which  are 
attached  orie  fixed  and  one  sliding  arm.     See  also  Biltmore  stick  and 
Tree  compass. 

G.,  Kluppe.     F.,  compas  forestier. 
Caliper,  v.     To  measure  diameters. 

G.,  Kluppieren.     F.,  mesurer  le  contour. 
Canopy.     See  Crown  cover. 

Capital.  This  factor  of  production  in  the  forestry  business  is  variously 
figured  according  to  what  parts  of  the  investment  are  referred  to  and 
what  basis  of  valuation  is  applied. 

Fixed  capital  refers  to  such  kinds  of  capital  as  are  not  used  up  in 
production,  hke  the  soil. 

Working  or  Operating  capital  refers  to  money  capital  needed  to  supply 
current  expenses  in  operating  a  forest. 

Soil  capital  refers  to  the  value  of  the  soil  figured  in  various  ways. 
Stock  capital  refers  to  the  value  represented  by  the  wood  material  of 
all  stands  comprising  a  forest  or  working  unit. 

Forest  capital  refers  to  soil  capital  and  stock  capital  combined. 
Base  capital  may  be  used  following  the  precedent  of  Pressler  in  his 
index  percent  for  the  combined  soil  and  working  capital. 

These  capitals  may  be  based  upon  various  kinds  of  values,  and  to 
secure  a  definite  meaning,  the  term  must  be  qualified  by  the  method, 
by  which  its  value  was  determined.  See  Value. 
Chance.  A  term  in  common  local  use,  more  or  less  synonymous  with 
Logging  unit,  which  see.  Not  favored  as  a  term  in  forest  manage- 
ment. 
Circumference  tape.     See  Diameter  tape. 

Clean-boled.     Being  free  or  cleared  of  branches.     Used  to  designate 
timber  with  a  satisfactory  length  of  clear  bole. 
G.,  Astrein.     F.,  depourvu  de  branches. 
Clean  cutting.     See  Reproduction,  methods  of. 
Cleaning.     See  Intermediate  fellings. 

Clear  and  Clearing.  1.  Clearing  in  common  parlance,  an  area  from 
which  all  or  nearly  all  forest  growth  has  been  removed. 


APPENDIX  303 

2.   The  process  of  removing  all  of  a  mature  crop  or  stand  at  one 
operation. 

G.,  Schlagraumung.     F.,  vidange. 

.3.  The  natural  loss  of  branches  through  withdrawal  of  light. 
Syn.:  self -pruning. 

G.,  Asterinigung.     F.,  elagage  naturel. 
Clear  length.     That  portion  of  the  stem  of  a  tree  free  from  lunbs  from  the 

ground  to  the  lowest  branch  or  branch  stub. 
Climax  type.     See  Forest  type. 
Closed.     See  Crown  density. 
Co-dominant.     See  Crown  class. 
Compartment.     See  Subdivision. 

Compartment  system.      {Obs.)      See   Reproduction   methods,   Shelter- 
wood. 
Composite  forest.     1.   A  forest  in  which  both  seedlings  and  sprouts  are 
used  in  reproduction.     The  seedling  growth  forming  the  overwood  or 
standards;  the  sprout  growth,  the  underwood. 

2.   A  forest  of  seedlings  and  sprouts  grown  up  together  naturally. 
Syn.:  sprout -seedhng  forest ;  coppice  with  standards. 
G.,  Mittelwald.     F.,  Taillis  sous  futaie  ou  compose. 
Conservative    lumbering.     {Ohs.)     Has    been   used    to    designate    any 
attempt  to  introduce  into  logging  operations  the  idea  of  providing  for  a 
future  crop,  or  at  least  a  second  cut. 
Control  book.     See  Working  plan  control. 

Conversion,  n.     A  change  from  one  silvicultural  method  to  another  as 
from  coppice  method  to  high  forest. 

G.,  Uberfiihrung,  Umwandlung.     F.,  conversion. 
Conversion  period.     The  period  during  which  the  change  from  one  system 
or  method  of  silvicultural  management  to  another  is,  or  is  to  be, 
effected. 
Coppice  forest,  coppice.     A  forest  consisting  wholly  or  mainly  of  sprouts. 
Syn.:  sprout  forest. 
G.,  Niederwald.     F.,  taillis  simple. 
Coppice  method.     See  Reproduction,  method  of. 
Coppice  shoot  or  sprout.     A  sprout  originating  from  a  coppice  stock  as 

opposed  to  a  seedling  stock.     See  Seedling  sprout. 
Coppice   with   standards.    See  Reproduction  method  and  Composite 
forest. 


304  APPENDIX 

Coupe  (French).     Cutting  or  Cutting  area.     Not  favored  as  a  term  in 

forest  management. 
Cross  section.     A  cut  across  the  trunk  or  branch  of  a  tree.     See  Basal 
area. 

G.,  Querschnitt.     F.,  section  transversale. 
Crown.     In  silvics,  the  upper  part  of  a  tree,  including  the  living  branches 
with  their  foliage. 

G.,  Krone.     F.,  cime. 
Crown  canopy.     See  Crown  cover. 

Crown  class.     All  trees  in  a  stand  occupying  a  similar  position  in  the 
crown  cover.     The  crown  classes  usually  distinguished  are: 

Dominant.  Trees  with  crowns  extending  above  the  general  level  of 
the  forest  canopy  and  receiving  full  Ught  from  above  and  partly  from 
the  side;  larger  than  the  average  trees  in  the  stand,  and  with  crowns 
well-developed  but  possibly  somewhat  crowded  on  the  sides. 

Co-dominant.  Trees  with  crowns  forming  the  general  level  of  the 
forest  canopy  and  receiving  full  light  from  above  but  comparatively 
little  from  the  sides;  usually  with  medium-sized  crowns  more  or  less 
crowded  on  the  sides. 

Intermediate.  Trees  with  crowns  below,  but  still  extending  into,  the 
general  level  of  the  forest  canopy,  receiving  a  little  direct  hght  from 
above  but  none  from  the  sides;  usually  with  small  crowns  considerably 
crowded  on  the  sides. 

Overtopped.  Trees  with  crowns  entirely  below  the  general  forest 
canopy  and  receiving  no  direct  light  either  from  above  or  from  the 
sides.  These  may  be  further  divided  into  oppressed,  usually  with  small, 
poorly  developed  crowns,  still  alive,  and  possibly  able  to  recover;  and 
suppressed  or  dying  and  dead. 
Crown  cover.  The  canopy  formed  by  the  crowns  of  all  the  trees  in  a 
forest,  or,  in  an  uneven-aged  forest,  by  the  crowns  of  all  trees  in  a  speci- 
fied crown  class. 

Syn. :  canopy,  crown  canopy,  leaf  canopy. 

G.,  Kronendach,  Beschirmung.     F.,  convert,  voute  foliacee. 

Crown  density.     An  expression  of  the  relation  of  crown  area  (or  crown 

cover)  to  the  land  area  involved,  measuring  the  extent  of  shading 

exercised  by  the  crowns,  with  due  regard  to  the  habit  of  the  species,  site, 

and  age.     It  is  usually  expressed  in  decimal  fraction  of  complete  cover. 

G.,  Beschirmungsdichte.     F.,  epaisseur  du  convert. 


APPENDIX  305 

The  degrees  of  crown  density  in  a  forest  may  be  expressed  by  the  fol- 
lowing terms,  and  fraction  of  a  full  crown  cover. 

Closed:  .8  to  i  (crown  cover  complete). 

G.,  geschlossen.     F.,  plein. 

Dense:  .6  to  .8  of  the  ground  shaded  by  the  crowns. 

G.,  dicht.     F.,  dense. 

Medium  or  broken:  .4  to  .6. 

G.,  liickig.     F.,  entrecoupe. 

Open:  less  than  .4  of  the  ground  shaded  by  the  crowns. 

G.,  Hcht.     F.,  clair. 
Cruise.     See  Estimate. 

Cull,  V.     1.   To  remove  trees,  especially  merchantable  ones,  from  a  forest 
without  regard  to  silviculture.     See  Lumber  manufacturing  terms. 

2.   In  grading,  to  place  in  the  lowest  grade. 
Cull,  n.     A  low  grade  of  lumber  or  a  rejected  tree  in  timber  estimating. 
Culled  forest.     See  Cut-over  forest. 
Current  increment.     See  Increment. 
Cut,  11.     The  amount  of  material  cut  or  to  be  cut  according  to  plan. 

Syn.:  felling  budget. 

G.,  Forstetat,  Hiebssatz.     F.,  budget  des  forets. 
Cut  over,  v.     To  cut  most  or  all  of  the  merchantable  timber  in  a  forest. 
Cut-over  forest.     Forest  from  which  most  or  all  of  the  merchantable  tim- 
ber has  been  cut. 

Syn.:  logged-over. 

Culled  forest  is  a  cut-over  forest  from  which  certain  species  or  sizes 
only  have  been  taken,  e.g.,  culled  for  pine  and  spruce. 
Cutting.     1.   In  nursery  and  planting  practice  a  portion  of  the  stem  or 
root  of  a  live  tree  used  for  propagation. 

G.,  Steckreis.     F.,  bouture. 

2.  The  process  of  felling  trees. 

G.,  Schlag,  Hieb.     F.,  coupe,  abatage. 

3.  An  area  on  which  the  trees  have  been  cut  or  are  to  be  cut. 
Syn.:  cutting  area;  felling  area. 

G.,  Abhiebsflache,  Schlag.     F.,  surface  coupee. 

Syn. :  felling.  There  being  a  difference  of  opinion  as  to  the  prefer- 
ence between  these  synonyms  in  the  sub-committee  and  the  collating 
committee,  the  latter  gives  them  equal  value,  recommending,  however, 
the  use  of  felling  (as  of  greater  term  quality)  wherever  a  substantive 


3o6  APPENDIX 

meaning  is  prominent  and  where  real  forestry  terms  are  involved,  as  in 

severance  felling,  felling  cycle,  felling  series,  felling  plan,  reserving  cut 

and  cuUing  where  the  common  verbal  sense  is  prominent,  as  in  cutting 

height,  cutting  limit. 
Cutting  area.     See  Cutting. 
Cutting  height.     See  Stump  height. 
Cutting  limit.     See  Diameter  limit. 
Cutting  plan.     See  Felling  plan. 
Cutting  series.     See  Felling  series. 
Cutting  cycle.     See  Felling  cycle. 

Damage  cutting.     See  Salvage  cutting  or  felling.     New  term. 
Damping  off.     The  succumbing  of  seedlings  to  a  certain  fungus  disease. 
Deforestation.     A  term  used  to  indicate  the  denuding  of  a  forest  area. 

G.,  Entwaldung.     F.,  deboisement. 
Dendrometer.     An  instrument  combining  height  and  diameter  measure. 

Capable  of  measuring  from  the  ground  diameters  at  any  point. 
Dense,  a.     See  Crown  density. 
Density  of  crop.     See  Stock  density. 
Development  class  or  stage.     Similar  to  age  class  and  tree  classes.     Mere 

descriptive  words  may  be  used  instead  of  age  and  measurement  to 

designate  a  stage  of  development  of  a  stand: 
Seedling  stage  or  seedling  growth,  a  stand  of  seedlings. 
Thicket  stage  or  brushwood,  a  stand  of  saplings. 
Polewood  stage,  a  stand  of  poles. 
Young  timber  stage,  a  stand  of  standards. 
Old  timber  stage,  a  stand  of  veterans. 
Diameter  breast-high.     The  diameter  of  a  tree  at  4J  feet  above  the 

ground.     (Abbreviation,  d.  b.  h.)     The  additional  abbreviations  o.  b. 

and  i.  b.  are  used  to  designate  whether  the  diameter  is  measured  outside 

or  inside  the  bark. 
Diameter  class.     All  trees  of  a  stand  whose  breast-high  diameters  fall 

within  prescribed  limits,  the  intervals  varying  usually  from  i  to  4 

inches,  fractions  being  rounded  off  to  the  nearest  full  inch  of  the  limit. 

The  diameter  classes  may  be  stated  by  numbers  of  trees  in  each  class 

on  the  unit  of  area  or  by  the  percentage  of  the  total  contents  of  the 

stand  represented  in  each,  or  by  area  occupied,  or  in  any  other  way. 

Diameter  classes  take  the  place  of  age  classes  in  the  selection  forest. 
G.,  Starkeklasse.     F.,  categoric  de  grosseur. 


APPENDIX  307 

Distribution  of  diameter  classes.     In  its  strict  sense,  the  location  and 
area  of  each  stand  of  a  given  diameter  class  in  the  forest;  in  a  general 
sense,  the  per  cent  of  area  occupied  by  each  diameter  class  in  the 
stand. 
Diameter  growth.     See  Increment. 

Diameter  limit.     The  smallest  (and  occasionally  largest)  size  to  which 
trees  or  logs  are  to  be  measured,  cut,  or  used.     The  points  to  which  the 
hmit  usually  refers  are  stump,  breast-height,  or  top. 
Diameter  tape.     A  tape  from  which  the  diameter  may  be  read  directly 

when  it  is  placed  around  the  tree. 
Dibble,  n.     A  tool  for  making  holes  for  planting  seeds  or  young  trees. 

G.,  Setzpfahl.     F.,  plantoir. 
Dibble  in,  v.     To  plant  seeds  or  young  trees  in  holes  made  with  a  dibble. 
Die  hammer.     See  Marking  hammer. 

Direct  seeding.     A  method  of  estabhshing  a  forest  artificially  by  sowing 
seeds  on  the  area  to  be  forested. 

Broadcast  seeding  method  is  an  application  of  direct  seeding  in  which 
seeds  are  sown  over  the  entire  area  to  be  forested. 

Partial  seeding  may  be  done  in  strips,  furrows  or  trenches,  plats  or 
spots  {see  Seed  spot) . 

G.,  Saeen,  Saat.     F.,  ensemencement,  semis. 
Disengagement  cutting  or  felling.     See  Intermediate  cuttings. 
District,  v.  To  make  a  subdivision  of  a  forest  into  units  on  map  or  ground. 

Syn.:  divide. 
District,  n.     An  administrative  subdivision.     See  Subdivision. 
Dominant.     See  Crown  class. 
DuflE.     See  Forest  floor. 
Empirical  yield  table.     See  Yield  table. 

Equalization  period.     The  period  during  which  it  is  planned  to  attain 
approximately  normal  stock  conditions. 
G.,  Einrichtungszeitraum. 
Estimate,  v.     To  determine  the  approximate  contents  of  trees  or  stands 

of  timber. 
Estimate,  n.     An  approximate  determination  of  size,  contents,  value  or 
anything  else;  more  specifically  of  the  volume  of  a  tree  or  stand. 
S>Ti.:  cruise. 
Even-aged.     Applied  to  a  stand  in  which  only  small  age  differences 
appear,  differences  varying  with  the  average  age  of  stand.    In  young 


3o8  APPENDIX 

stands,  age  differences  should  not  be  more  than  lo  or  20  years;    in 
mature  stands,  not  more  than  30  or  40  years. 

G.,  gleichalteriger  Bestand.     F.,  peuplement  uniform. 

Expectation  value.     See  Value. 

Exposure.     Sec  Aspect. 

Factors  of  locality.     See  Site. 

Fail  spot  or  place.  A  place  where  natural  or  artificial  reproduction  has 
failed. 

G.,  Fehlstelle.     F.,  vide. 

Felling.  Syn. :  cutting.  The  term  felling  is  preferred  by  the  collating 
committee  for  its  better  term  quality,  especially  where  substantive 
meaning  is  prominent.     See  under  Cutting. 

Felling  age.     See  Rotation. 

Felling  area.  An  area  on  which  the  trees  have  been  cut  or  are  to  be 
cut. 

Felling  budget.     See  Cut. 

Felling  cycle.     The  planned  interval  between  fellings  or  cuts  on  the  same 
forest  area.     See  also  Reproduction,  Selection  method. 
Syn. :  period  of  return. 

Felling  plan.     See  under  Working  plan. 

Felling  series.  An  aggregation  of  stands  into  a  proposed  or  actual 
sequence  of  felling  areas,  the  object  being  a  distribution  of  felling  areas 
for  administrative  reasons  or  to  secure  a  final  satisfactory  distribution 
or  location  of  age  classes,  especially  to  avoid  damage  by  windfall  and 
insects  due  to  uniformity  of  stand  and  size  of  felling  area.  It  is 
intended  to  interrupt  a  regular  sequence  of  age  classes. 
Syn. :  cutting  series. 
G.,  Hiebszug.     F.,  serie  de  coupes. 

Final  cutting.    See  Reproduction,  Shelterwood  method. 

Final  yield.     See  Yield. 

Financial  maturity.    See  Maturity. 

Financial  rotation.    See  Rotation. 

First  growth.     See  Old  growth. 

Forest,  n.  In  common  usage,  a  large  tract  of  land  covered  with  trees; 
more  exactly,  a  tract  of  land,  more  or  less  extensive,  covered  more  or 
less  densely  with  trees  of  useful  character,  viewed  from  the  standpoint 
of  economic  use  and  development.  A  species  of  woodland  or  woods, 
which  is  the  generic  term  for  the  wooded  condition  of  the  land. 


APPENDIX  309 

Timherland  or  Timber  is  used  to  designate  ability  to  furnish  at  once 
logs  or  material  for  commercial  purposes. 

Woodlot.  Any  small  tract  of  forest,  usually  the  forested  portion  of  a 
farm. 

Forest.     In  finance,  refers  to  the  combination  of  soil  and  stand. 

Forest,  v.     To  establish  a  forest  either  by  natural  or  artificial  means. 

Forest  capital.     See  tmder  Capital. 

Forest  cover.  All  trees  and  other  woody  plants  (underbrush)  covering 
the  ground  in  a  forest. 

Forest  economics.  A  comprehensive  term  including  all  matter  referring 
to  the  position  of  forests  in  public  affairs. 

Forest  economy.  A  comprehensive  term  including  all  matter  dealing 
with  the  business  aspects  of  forest  management. 

Forest  expectancy  value.     See  under  Value. 

Forest  finance.  That  branch  of  the  science  of  forestry  which  relates  to 
the  forest  as  an  investment.  It  includes  two  distinct  subjects,  forest 
valuation  and  forest  statics;  the  first  concerning  itself  with  valuations 
of  soil  and  growing  stock,  increment,  and  damage;  the  second  concerns 
itself  with  a  comparison  of  the  financial  results  of  different  methods 
of  treatment  and  other  questions  of  profitableness  and  financial 
effects. 

G.,  Waldwertrechnung  =  forest  valuation:  forstliche  Statik  =  forest 
statics. 

Forest  fire.     See  under  Protection  terms. 

Forest  floor.  A  term  used  in  forest  description  to  designate  only  the 
deposits  of  vegetable  matter  on  the  ground  in  a  forest. 

Litter  includes  the  upper,  but  shghtly  decomposed  portion  of  the 
forest  floor;  humus,  the  portion  in  which  decomposition  is  well  ad- 
vanced. See  Humus.  An  intermediate  layer  of  more  or  less  decom- 
posed organic  matter  below  the  litter  may  be  designated  as  duff. 

Forest  influences.  All  effects  resulting  from  the  presence  of  the  forest 
upon  health,  cHmate,  streamflow,  and  economic  conditions. 

Forest  inventory.     See  Forest  survey. 

Forest  management.  The  practice  or  application  of  forestry  in  the  con- 
duct of  the  forest  business. 

G.,  Forstbetrieb.     F.,  exploitation  des  forets,  amenagement. 
The  collating  committee  prefers  to  see  the  term  used  as  defined, 
instead  of  as  an  equivalent  to  forest  economy  as  a  collective  name  for 


3IO  APPENDIX 

the  subjects  which  deal  with  business  problems  (see  Forestry)  as  sep- 
arated from  forest  crop  production. 
Forest  mensuration.     That  branch  of  forestry  which  deals  with  the  deter- 
mination of  the  volume  of  stands,  trees,  logs  and  other  timber  products, 
and  with  the  study  of  growth  and  yield  of  trees  and  stands. 

G.,  Holzmesskunde.     F.,  dendrometrie. 
Forest  organization.     The  branch  of  forestry  wnich  concerns  itself  with 
the  organization  of  a  forest  property  for  management  and  its  main- 
tenance, ordering  in  time  and  place  the  most  advantageous  use  of  the 
property,  with  the  ultimate  aim  of  securing  a  sustained  yield. 

Syn.:  forest  regulation. 

G.,  Betriebsregulierung,  Forsteinrichtung.     F.,  amenagement. 

Note:  In  the  past  both  forest  regulation  and  forest  organization  have 
been  used  indiscrimuiately.  In  the  absence  of  any  English  word 
exactly  equivalent  to  the  German  "Forste-mrichtung,"  both  terms  may 
well  continue  to  be  used. 
Forest  per  cent.  In  finance,  the  rate  of  interest  earned  by  the  forest 
capital.  Current  annual  forest  per  cent  (index  per  cent)  and  mean 
annual  forest  per  cent  are  distinguished. 

In  economics,  the  proportion  of  land  of  a  given  State  or  country 
covered  by  forest. 
Forest  plantation.     Forest  growth  established  by  setting  out  young  trees 
or  by  sowing  seed. 

G.,  Pflanzung,  Kultur.     F.,  plantation. 
Forest  planting.     The  artificial  establishment  of  a  forest  by  setting  trees, 
or  with  certain  species  by  planting  cuttings.     In  general  sense  includ- 
ing also  direct  seeding  (quid  vide).     Terms  of  forest  planting  are  as 
follows: 

Planted  and  Planting  area.  Land  which  has  been  artificially  stocked 
with  forest  trees,  or  is  to  be  so  stocked. 

Planting  plan.     A  detailed  scheme  for  forest  planting  on  a  given  area. 

Planting  stock.  Trees  or  cuttings  used  in  forest  planting.  The  age 
and  history  of  the  trees  are  indicated  by  figures,  e.g.,  2-0,  two-year-old 
seedlings,  or  2-1,  two-year-old  seedlings  which  have  remained  one  year 
in  transplant  beds  or  rows. 

Ball  planting.  A  method  of  transplanting  young  trees  with  balls  or 
lumps  of  earth  around  the  roots. 

G.,  Ballenpflanzung.     F.,  plantation  en  motte. 


APPENDIX  311 

Bunch  planting.  (Obs.)  A  method  of  planting  in  which  two  or 
more  plants  are  set  in  one  hole. 

Hole  method.  A  method  of  planting  forest  trees  in  which  the  trees 
are  set  in  a  hole;  to  be  distinguished  from  the  slit  method. 

G.,  Lochpflanzung.     F.,  plantation  par  potets. 

Slit  method.  A  method  of  forest  planting  in  which  a  slit  or  cleft  is 
made  with  the  planting  tool,  the  tree  inserted  and  the  soU  firmed  into 
place  after  withdrawal  of  the  tool;  to  be  distinguished  from  the  hole 
method.  According  to  the  implement  in  use,  the  method  is  desig- 
nated mattock-slit  or  spade-slit,  etc. 

G.,  Klemmpflanzung,  Spaltpflanzung.     F.,  plantation  en  fente. 

Mound  planting.  A  method  of  planting  on  wet  ground,  in  which  the 
seeds  or  young  trees  are  planted  on  mounds,  ridges,  or  hills. 

Syn. :  hill  planting,  ridge  planting. 

G.,  Hiigelpflanzung.     F.,  plantation  en  buttes. 

Row  planting.  An  arrangement  of  trees  in  forest  planting  in  which 
they  are  set  in  rows. 

Syn. :  regular  planting. 

G.,  Reihenpflanzung.     F.,  plantation  en  lignes. 

Trench  planting.  A  method  of  planting  in  which  the  young  trees 
are  set  in  trenches  or  furrows. 

Pit  planting  when  plants  are  set  in  small  depressions  or  pits  instead 
of  continuous  trenches. 

Syn. :  furrow  planting. 

Repair  planting.     After-culture,  filhng  out  fail  places  by  planting. 

G.,  Nachbesserung.     F.,  regarnissage. 

According  to  the  arrangement,  row  planting  is  designated  as  follows: 

Rectangular  planting.  An  arrangement  in  which  the  trees  are  set  at 
the  corners  of  successive  rectangles. 

G.,  Quadratpflanzmig,  Quadrat verband.     F.,  plantation  en  carre. 

Triangular  planting.  An  arrangement  in  which  the  trees  are  set  out 
at  the  corners  of  successive  triangles. 

G.,  Dreieckverband.     F.,  plantation  en  triangle. 

Quincunx  planting.  An  arrangement  in  which  the  trees  are  set  in 
the  center  and  at  the  corners  of  successive  squares. 

G.,  Fiinfverband,  Kreuzpflanzung.     F.,  plantation  en  quinconce. 

Seeding  lath,  seeding  trough.  Planting  tools  used  to  secure  an  even 
distribution  of  seed  in  drills  of  the  seed  bed  (nursery  practice). 


312  APPENDIX 

Seed  Iwrn,  seed  flask,  etc.  Planting  tools  designed  to  distribute  a 
uniform  amount  of  seed  in  direct  seeding  in  seed  spots. 

Forest  policy.  The  attitude  toward  forests  and  general  method  of  ad- 
ministration of  public  interests  in  forests  by  the  State. 

Forest  regiUation.     See  Forest  organization. 

Note:  In  the  past  both  forest  regulation  and  forest  organization 
have  been  used  indiscriminately.  In  the  absence  of  any  English  word 
exactly  equivalent  to  the  German  "Forstcinrichtimg,"  both  terms  may 
well  continue  to  be  used. 

Forest  rent.     See  under  Rent. 

Forest  rental  value.     See  under  Value. 

Forest  survey.  The  gathering  and  tabulation  of  all  data  in  regard  to 
forest  lands  including  plane  and  topographic  surveying,  mapping, 
timber  estimates,  forest  description,  grazing  data  and  land  classifica- 
tion, type  and  site  determination,  involving  all  the  work  of  ever>^  kind 
(including  the  construction  of  volume,  growth  and  yield  tables)  neces- 
sary for  the  making  of  a  working  plan.  Forest  surveys  may  be  partial 
or  complete,  more  or  less  intensive  or  extensive,  and  of  varying  degree  ■ 
of  accuracy. 

Syn.:  stock-taking  in  part. 

Forest  tree  nursery.  An  area  upon  which  young  trees  are  grown  for 
forest  planting. 

Seedling  and  Transplanting  nursery,  permanent  and  temporary,  may 
be  distinguished. 

G.,  Saatkamp,  Baumschule.    F.,  pepiniere. 

Forest  type.  A  descriptive  term  used  to  group  stands  of  similar  charac- 
ter as  regards  composition  and  development  due  to  given  physical  and 
biological  factors,  by  which  they  may  be  differentiated  from  other 
groups  of  stands.  The  term  suggests  repetition  of  the  same  character 
under  similar  conditions. 

A  type  may  be  termed  temporary  to  express  the  expectation  of  a 
change,  if  its  character  is  due  to  passing  influences  (logging,  fire,  etc.) ; 
perma7ient  if  no  change  is  expected  and  the  character  is  due  to  physical 
and  biological  (natural)  factors  alone;  climax  if  it  is  intended  to  indi- 
cate the  character  as  the  ultimate  stage  of  a  succession  of  temporary 
types. 

A  Cover  type  is  a  forest  type  now  occupying  the  ground,  no  impHca- 
tion  being  conveyed  as  to  whether  it  is  temporary  or  permanent. 


APPENDIX  313 

Forest  utilization.  That  branch  of  forestry  which  concerns  itself  with 
the  operation  of  harvesting  and  marketing  the  forest  crop  and  other 
resources  of  the  forest. 

G.,  Forstbenutzung.     F.,  technologic  forestiere. 

Forestation.  The  establishment  of  forest  naturally  or  artificially  upon 
areas  where  it  is  at  present  absent  or  insufiicient.  If  distinction  is 
desired,  "  afforestation  "  may  be  used  to  designate  the  planting  of  open 
ground,  "  reforestation  "  to  designate  previous  wooded  condition. 

Forester,  n.     1.   One  who  is  trained  to  practice  forestry  as  a  profession. 
G.,  Forstmann.     F.,  forestier. 
2.   A  title  or  designation  of  position. 

Forestry.  The  science  and  art  of  managing  forests  in  continuity  for 
forest  purposes,  i.e.,  for  wood  suppUes  and  forest  influences. 

G.,  Forstwirtschaft,  Forstwesen,  Forstwissenschaft.  F.,  science 
forestiere,  foresterie. 

The  main  branches  of  forestry  are  Forest  policy.  Silviculture,  Forest 
economy  or  Forest  management  (q.  v.)  (including  Forest  mensuration, 
organization  or  regulation,  administration  and  finance).  Forest  protec- 
tion and  Forest  utilization. 

Form  class.  Classification  of  trees  according  to  taper,  from  very  tapering 
to  full-boled  (for  use  with  Schiffel's  form  quotient). 

Form  constant.  The  numerical  difference  between  the  form  quotient 
and  the  form  factor  (C  =  Q  —  F).  The  form  constant  remains  prac- 
tically the  same  for  a  given  species,  no  matter  of  what  height  or  diam- 
eter. 

Form  factor.  The  form  factor  of  a  tree  is  the  ratio  between  its  volume 
and  that  of  a  geometric  sohd,  usually  a  cyhnder,  having  the  same 
diameter  and  height.  The  volume  of  the  sohd  (or  cylinder)  is  taken 
as  a  unit,  "  i,"  the  volume  of  the  tree  or  trees  is  expressed  as  a  deci- 
mal. Form  factors  are  classified  according  to  the  point  of  diameter 
measurement  (base,  d.  b.  h.,  top),  the  portion  of  the  tree  included 
(tree-stem,  merchantable  portion,  etc.),  the  geometrical  figure  used  as  a 
basis  of  comparison  (cylinder,  cone,  frustum) ,  the  unit  of  measure  used 
(cubic  foot,  foot  B.  M.),  and  may  refer  to  single  trees  or  stands.  In 
this  classification  eleven  qualifications  have  been  so  far  considered. 
Common  usage  implies  breasthigh  measurement,  cylindrical  compari- 
son, cubic  foot  unit  and  single  stems.  The  term  Absolute  form  factor 
is  used  if  the  base  diameter  is  measured  at  the  base  of  the  tree;  Normal 


314  APPENDIX 

Jorm  factor,  if  the  measurement  is  made  at  a  varying  height  which 

bears  a  constant  ratio  to  the  total  height  of  the  tree. 
G.,  Formzahl.     F.,  coefficient  de  forme. 
Form  height.     1.   The  product  of  height  and  form  factor,  tabulated  for 

convenience  of  calculating  cubic  contents  of  trees  or  stands. 
G.,  Formhohe,  Richthohe. 
Form  quotient.     The  quotient  of  the  breasthigh  diameter  of  a  tree  into 

the  diameter  measured  at  any  height  above  the  d.  b.  h.,  usually  at 

i,  ^,  or  f  of  the  height  of  the  tree. 
Freeing  (setting  free).     See  Intermediate  (disengagement  and  liberation) 

cutting. 
Fully  stocked.     The  condition  of  a  stand  containing  as  many  trees  or 

material  as  it  normally  can  for  the  species,  site,  and  age.     See  Stock, 

Overstocked. 
Full-boled.     As  appHed  to  the  trunk  of  a  tree,  approaching  the  cylindrical 

form.    See  Form  class. 

G.,  vollholzig.     F.,  a  fut  soutenu. 
Gradation  of  age  classes.     See  Age  class. 
Grading.     In  description  mensuration,  and  utilization  the  process  of 

differentiating  the  crop  into  assortments  {q.  v.)  or  classes  of  material. 
Ground  cover.     A  term  used  in  forest  description  to  designate  all  herba- 
ceous plants  growing  in  a  forest;  such  as  ferns,  mosses,  grasses,  and 

weeds. 

G.,  Bodendecke.     F.,  couverture  du  sol. 
Group  method.     See  Reproduction  method. 
Growing  stock.     See  Stock. 
Growth.     See  Increment. 

Growth  table.     A  tabular  statement  showing  the  growth  data  of  individ- 
ual trees  or  stands.     See  Increment. 
Habit.     The  general  form  or  arrangement  of  stem,  roots,  and  branches, 

or  of  the  entire  tree,  possessed  in  common  by  a  species  in  a  given 

habitat. 
Heel  in,  v.     To  store  young  trees  prior  to  planting  by  placing  them  against 

the  side  of  a  trench  and  covering  the  roots  with  earth. 
Height  class.     One  of  the  arbitrary  divisions  of  the  trees  of  a  stand  on  the 

basis  of  height.     The  division  is  usually  by  intervals  of  lo  feet. 
G.,  Hohenklasse.     F.,  classe  de  hauteur. 
Height  measure.     See  Hypsometer. 


APPENDIX  315 

High  forest.     A  forest  originating  from  seed. 
Syn.:  timber  forest. 

G.,  Hochwald;  Samenwald.     F.,  futaie,  haute  futaie. 
Hole  method.     See  under  Forest  planting. 

Hold-over.     A  tree  reserved  from  harvest  to  grow  through  a  second  rota- 
tion.    See  Reserve. 

G.,  Ueberhalter.     F.,  reserve. 
Humus,  11.     That  portion  of  the  forest  floor  {q.  v.)  in  which  decomposition 
of  the  Htter  is  so  far  advanced  that  its  original  form  is  not  distinguish- 
able.    Humus  in  a  condition  favorable  to  forest  growth  is  said  to  be 
mild,  neutral,  or  sweet.     Humus  harmful  to  forest  growth,  owing  to  the 
presence  of  humic  or  similar  acids  or  colloids  produced  by  decomposi- 
tion under  excess  of  moisture  and  lack  of  air,  is  said  to  be  sour.     Humus 
incompletely  decomposed  is  called  raw  humus. 
G.  and  F.,  Humus. 
Hypsometer.     An  instrument  for  measuring  heights,  especially  of  trees. 
Improvement  felling.     See  under  Intermediate  cuttings. 
Income.     In  forest  finance,  the  gross  income  represents  money  returns 
from  which  no  expenses  have  been  deducted;  net  income  results  by 
deducting  all  actual  expenses  charged  in  book  account,  including 
interest  on  borrowed  capital,  but  not  the  calculated  interest  on  invest- 
ment, which  enters  in  determining  profit. 

G.,  Geldertrag,  Einkiinfe,  Erlos.     F.,  revenu. 

G.,  Rohertrag,  Rohgeldertrag,  Brutto  Geldertrag,  Erlos  im  Ganzen, 
Gesamtgeldein  nahmen. 
Final  income,  returns  from  final  harvest. 
G.,  Haubarkeitsertrag,  Abtriebsertrag. 
Intermediate  income,  returns  from  stands  not  yet  mature. 
G.,  Nebennutzungs:,  Zwischennutzungs-,  Vornutzungs-ertrag,  -gel- 
dertrag. 
Income  rotation.     See  Rotation. 
Income  table.    See  Yield  table. 
Increment.     Syn.:  accretion. 

The  increase  in  diameter,  sectional,  basal  area,   height,  volume, 

quality  or  value  of  a  tree  or  stand.     If  distinction  between  the  two 

terms  is  desired,  accretion  should  be  reserved  for  directly  measurable, 

increment  for  calculated  increases. 

Increment  is  differentiated  with  reference  to  time  as  current  annual 


3l6  APPENDIX 

increment  =  the  increment  for  a  specific  year  (abbreviation,  c.  a.  i.) 
(G.,  laufend  jahrlicher  Zuwachs);  periodic  increment  =  the  increment 
during  a  specific  period  of  years;  mean  annual  increment  {m.  a.  i.)  =  the 
total  increment  divided  by  the  age  (G.,  Gesammtalterszuwachs) ;  pe- 
riodic annual  increment  {p.  a.  i.)  =  the  increment  for  a  specified  period 
of  years  divided  by  the  number  of  years  in  the  period;  usually  used 
in  lieu  of  the  current  increment  (G.,  periodischer  Durchschnittszu- 
wachs). 

Quality  increment  is  the  increase  in  value  per  unit  of  volume  due  to  its 
augmented  intrinsic  worth  with  size  or  age. 

G.,  Qualitatszuwachs. 

Price  increment  is  the  increment  in  the  sale  value  of  forest  products 
independent  of  quality  increment,  due  to  market  conditions. 

G.,  Teuerungszuwachs. 

Value  increment  is  the  increase  in  value  of  a  tree  or  stand  due  to  com- 
bined volume,  quality  and  price  increment. 

G.,  Wertszuwachs. 

Increment  may  be  expressed  in  absolute  numbers  or  as  increment  per 
cent  per  annum  based  on  present  or  on  past  quantity  as  loo. 

See  also  Index  per  cent. 
Increment  borer.     An  instrument  for  determining  the  rate  of  growth  in 
diameter  of  standing  trees.     It  consists  of  a  hollow  auger,  which,  when 
bored  into  a  tree  at  right  angles,  extracts  a  core  on  which  the  annual 
rings  show. 

Syn.:  accretion  borer;  Pressler  borer. 

G.,  Zuwachsbohrer.  F.,  sonde  de  Pressler. 
Index  per  cent.  The  increase  in  value  of  a  tree  or  of  a  stand,  due  to  the 
combined  volume,  quality  and  price  increments,  expressed  as  an  annual 
per  cent  of  its  present  value.  The  interest  rate  at  which  a  given  stand 
pays  interest  by  its  value  increment  on  its  current  value  plus  Base 
capital  {q.  v.)  as  capital;  used  to  determine  financial  maturity  or  felling 
age  by  comparison  with  a  demanded  business  rate. 

G.,  Weiserprozent;  Forstprozent.  F.,  taux  maximum  du  revenu. 
Index  stand.  A  mature  stand  used  as  a  basis  for  conclusions,  or  an 
index  of  condition  (volume)  of  the  stand  in  former  years,  or  of  other 
immature  stands,  on  the  supposition  that  the  stems  of  the  mature 
stand  represent  the  dominant  stand  of  the  earlier  periods  on  the  same 
site. 


APPENDIX  317 

G.,  Weiserbestand.     F.,  peuplement  type. 
Index  tree.     A  mature  tree  utilized  as  an  index  of  condition  of  immature 

trees.     See  Index  stand. 
Interlucation.     New  term.     A  severe  opening  up  of  a  stand  to  light 
beyond  the  degree  of  severe  thinning  in  order  to  secure  a  large  increase 
of  diameter  on  the  remaining  stand  before  final  harvest.     Usually 
accompanied  by  underplanting.     See  Intermediate  cuttings. 
Intermediate.     See  Crown  class. 

Intermediate.  Refers  to  operations  or  occurrences  taking  place  during 
the  rotation  before  the  final  harvest  of  a  stand,  such  as  Intermediate 
cuttings  or  fellings  {q.  v.),  Intermediate  yield  or  Income  or  Returns. 
Intermediate  cuttings  or  fellings.  Cuttings  made  in  a  stand  between  the 
time  of  its  formation  and  its  final  harvest.  It  includes  cleanings, 
improvement  cuttings  and  thinnings. 

G.,  Zwischennutzung;  Vornutzung.     F.,  exploitation  intermediaire. 
Cleaning.     Cutting  made  in  a  stand  not  yet  past  the  sapling  stage 
for  the  purpose  of  removing  trees  of  undesirable  form  or  species,  which 
are  injuring  or  are  likely  to  injure  those  of  greater  promise. 
Syn.:  weeding. 

G.,  Reinigungshib,  Durchplaenterung,  Durchlauterung.  F.,  coupe 
de  nettoiement. 

A  disengagement  cutting  or  felling.  A  cleaning  in  a  stand  of  small 
saplings  with  the  specific  purpose  of  checking  or  removing  trees  of 
undesirable  species  which  are  overtopping  desirable  trees  or  may  later 
shade  them. 

G.,  Kronenfreihieb.  F.,  degagement  de  la  cime. 
Improvement  cutting  or  felling.  A  cutting  in  a  forest  which  has  passed 
the  sapling  stage,  the  main  object  being  to  remove  trees  of  undesirable 
form,  condition  and  species.  It  is  always  a  felling  for  the  purpose  of 
bringing  the  stand  into  better  condition  and  composition  for  silvicul- 
tural  management. 

G.,  Verbesserungshieb.     F.,  coupe  d'amelioration. 
Salvage  cutting  or  felling.     Removal  of  trees  killed  or  injured  in  a 
forest  by  fire,  insects,  fungi,  or  other  harmful  agencies,  with  the  purpose 
of  utilizing  merchantable  material  and  preventing  the  spread  of  insects 
and  disease. 

G.,  Totalitatshieb.     F.,  coupe  accidenteUe. 

Liberation  cutting  or  felling.    Is  an  improvement  cutting  by  which 


3i8  APPENDIX 

young  growth  is  freed  (set  free)  from  oppression  by  removal  of  woK 
trees. 

G.,  Freistellen.     F.,  degager. 

Severance  felling  or  cutting.  The  clearing  of  a  narrow  strip  on  the 
border  of  a  young  stand  to  stimulate  the  root  development  and  reten- 
tion of  branches  of  the  bordering  trees,  producing  a  windfirm  mantle, 
and  thus  preparing  them  for  subsequent  exposure  to  wind  when  an 
older  stand  on  the  windward  side  of  the  strip  has  to  be  removed  before 
the  utilization  of  the  younger  stand. 

Thinning.  A  cutting  made  in  immature  stands  after  the  saphng 
stage  for  the  purpose  of  increasing  the  rate  of  growth  of  those  trees 
which  are  left. 

G.,  Durchforstung.     F.,  eclaircie. 

Degrees  of  thinning  are  indicated  by  tne  following  grades.  They 
may  be  gauged  by  volume  and  by  number  of  trees  removed. 

Grade  A  —  light.     A  removal  of  dead  and  dying  trees. 

Grade  B  —  moderate.  A  removal,  in  addition,  of  all  suppressed  trees 
and  the  poorest  intermediate  trees. 

Grade  C  —  heavy.  A  removal,  in  addition,  of  the  rest  of  the  inter- 
mediate class  of  trees. 

Grade  D  —  very  heavy.  A  removal,  in  addition,  of  many  of  the  co- 
dominant  trees. 

German  and  Austrian  experiment  stations  recognize  four  grades; 
Gayer  1  recognizes  three  grades,  as  follows: 

Light  (G.,  Schwach).     Removal  of  dead  and  whoUy  suppressed. 

Medium  (G.,  Mittelstark).  Removal  of  suppressed  and  the  greater 
portion  of  the  dominated  trees  (intermediate  class). 

Heavy  {G.,  Stark).  In  addition,  cutting  operations  in  the  co-domi- 
nant class. 

Interlucation.  A  severe  opening  up  of  a  stand.  Sec  fuller  definition 
under  its  letter. 

Selection  thinning.     A  thinning  in  which  always  the  stoutest  trees 
are  removed,  as  in  the  selection  method  of  regeneration  (Borggreve). 
Intermittent  management.     The  management  of  a  forest  for  a  periodic 
instead  of  annual  yield. 
G.,  Aussetzender  Betrieb. 

1  Der  Waldbau,  Dr.  Karl  Gayer,  Berlin,  1888. 


APPENDIX  319 

Interplant,  To  set  out  young  trees  among  existing  young  seedling 
growth,  planted  or  natural;  applicable  also  to  planting  land  partly 
occupied  by  brushwood. 

Intolerant.  Incapable  of  enduring  much  shade,  varying  with  species, 
age,  and  site. 

Syn.:  light  demanding. 

G.,  lichtbediirftig.     F.,  temperament  robuste. 

Large  pole.     See  Tree  class. 

Large  sapling.     See  Tree  class. 

Lath  screen.     See  Shade  frame. 

Leader.     The  terminal  shoot  of  the  main  stem. 

Leaf  canopy.     See  Crown  cover. 

Leaf  litter.     See  Forest  floor. 

Leaf  mold.     See  Humus. 

Liberation  cuttings.     See  Intermediate  cuttings. 

Lift,  V.     To  loosen  and  remove  seedlings  from  the  seedbed  in  a  nursery. 

Light-demanding.     See  Intolerant. 

Litter.     Sec  under  Forest  floor. 

Locality.     See  Site. 

Log  rule.  1.  A  tabular  statement  indicating  the  estimated  or  calculated 
amount  of  lumber  which  can  be  sawed  from  logs  of  given  lengths  and 
diameters. 

2.  A  graduated  rule  (usually  made  of  wood)  for  measuring  the 
diameters  and  volumes  of  logs,  the  number  of  board  feet  in  logs  of  given 
diameters  and  lengths  being  shown  upon  the  rule.  (Usually  called 
Scale  stick  {q.  v.)  ). 

Log  scale.     See  Scale  stick. 

Logging  unit.     A  part  of  a  forest  which  can  conveniently  be  made  the 
basis  of  an  individual  logging  operation. 
Syn.:  chance;  logging  chance. 

Lot.     See  Subdivision. 

Low  pole.     See  Tree  class. 

Lumber  rule.     See  Board  rule. 

Lumber  scale.     See  Board  rule. 

Management.     See  Forest  management. 

Marginal  seeding.     See  Reproduction  (strip)  method. 

Marking  hammer.  A  tool  used  for  marking  trees  or  logs  or  other  prod- 
ucts with  various  characters,  signs,  numbers,  etc. 


320  APPENDIX 

Mature  forest.  A  forest  or  stand  which  has  reached  its  age  of  utilization 
(commercially).  The  meaning  of  maturity  differs  with  the  object  of 
management,  and  to  the  forester  is  a  matter  of  calculation  on  various 
bases.  Biologically,  maturity  would  refer  to  the  age  of  seed  produc- 
tion; physically,  to  cessation  of  height  growth.  Financial  maturity  is 
attained  when  the  highest  forest  income  or  interest  (which  occurs  when 
the  index  per  cent  is  equal  to  the  demanded  business  per  cent) ,  or  forest 
rent,  or  soil  rent,  or  otherwise  financially  best  results  can  be  secured. 
After  this  point  of  maximum  result  is  passed  the  forest  income  decreases 
and  the  forest  is  said  to  be  "  financially  overmature."  See  also  Rotation. 
Syn.:  ripe. 
G.,  finanzielle  Hiebsreife. 

Mean  annual  forest  per  cent.     See  Forest  per  cent. 

Mean  annual  increment.     See  Increment. 

Mean  sample  tree.  A  tree  of  representative  form  which  in  diameter, 
height,  and  volume  is  an  average  of  the  trees  in  a  group  or  stand. 

Medium.     See  Crown  density. 

Merchantable.  A  term  to  designate  the  portion  of  trees  or  stands  which 
can  be  marketed  under  given  economic  conditions,  usually  refers  to 
log  material  only. 

Merchantable  length  refers  to  the  marketable  length  of  log  in  a  tree. 
Merchantable  volume  refers  to  the  marketable  volume. 

Merchantable  form  factor.     See  Form  factor. 

Middle  forest.     {Obs.)     See  Composite  forest. 

Mild  humus.     See  Humus. 

Mixed  forest.  Forest  composed  of  trees  of  two  or  more  species.  In 
practice  usually  a  forest  in  which  at  least  20  per  cent  are  trees  of  other 
than  the  leading  species. 

G.,  gemischter  Bestand.     F.,  peuplement  melange. 

Model  forest.    See  Normal  forest. 

Mother  tree.     See  Seed  tree. 

Mound  planting.     See  Forest  planting. 

Natviral  pruning.     See  Pruning. 

Natural  reproduction.     See  Reproduction. 

Net  income.     Sec  Income. 

Normal.  Used  as  in  common  parlance  in  varying  sense  as  conforming  to 
a  standard,  rule  or  principle,  a  model,  or  as  denoting  an  average  of 
conditions,  or  the  best  of  conditions. 


APPENDIX  321 

G.,  normal.     F.,  normal. 

Normal  age  classes.  The  presence  of  a  complete  series  of  age  classes 
corresponding  to  the  rotation  {see  Age  class). 

Normal  age  class  distribution.  Such  distribution  of  age  classes  as 
will  permit  annual  or  periodic  fellings  to  be  made  without  damage  to 
adjoining  stands. 

Syn.:  normal  age  class  arrangement. 

Normal  increment.  The  best  average  increment  attainable  by  given 
species  on  given  sites,  as  represented  in  normal  yield  tables. 

Normal  forest.  A  standard  with  which  to  compare  an  actual  forest 
to  bring  out  its  deficiencies  for  sustained  yield  management ;  the  con- 
ception of  an  ideally  regulated  or  organized  forest;  a  forest  with 
normal  increment,  normal  age  classes  in  size  and  distribution,  and 
normal  stock. 

Normal  growing  stock  or  Normal  stock.  The  amount  of  material 
represented  by  the  stands  in  a  normal  forest;  practically,  the  contents 
of  the  normal  age  classes  as  represented  in  normal  yield  tables. 

Normal  yield  table.  An  accepted  standard  yield  table  with  which 
to  compare  actual  yields.  The  statements  of  a  normal  yield  table  are 
derived  as  an  average  from  the  best  producing  fully  stocked  areas  for 
given  species  and  sites.  If  a  normal  forest  were  not  merely  an  idea, 
but  actually  attainable,  the  normal  yield  table  would  represent  its  pro- 
ductivity and  stock. 

Normal  stand.     A    stand    fully    stocked   and   in   proper   growing 
conditions,  conforming  to  the  yield  table  and  having  normal  incre- 
ment. 
Normal  form  factor.     See  Form  factor. 

Nurse  tree.    A  tree  which  protects  or  fosters  the  growth  of  another  in 
youth. 

G.,  Schutzholz.     F.,  essence  d'abri. 
Nursery.     See  Forest  tree  nursery. 
Old  growth.     See  Virgin  forest. 
Open,  a.    See  Crown  density. 
Oppressed.     See  Crown  class. 
Organization.     See  Forest  organization. 
Over-cut.     The  cutting  of  a  quantity  of  timber  in  excess  of  the  annual 

growth  of  the  forest  or  of  the  annual  felling  budget. 
Overmature  forest.    Forest  on  which,  as  the  result  of  age,  growth  has 


322  APPENDIX 

almost  entirely  ceased,  and  decay  and  deterioration  have  begun.     See 
also  Mature  forest. 

Over-stock.  A  growing  stock  greater  than  the  normal  growing  stock. 
In  natural  regeneration,  a  condition  of  an  excessive  number  of  indi- 
viduals hindering  each  other  in  development  and  retarding  desirable 
differentiation  into  crown  classes. 

Overwood.     See  Composite  forest. 

Park  forest  A  forest  in  which  the  trees  stand  apart  from  one  another 
or  in  detached  groups.  A  very  open  forest  in  which  usually  also  the 
characteristic  forest  floor  is  replaced  by  grasses. 

Periodic  annual  increment.     See  Increment. 

Periodic  increment.     See  Increment. 

Permanent  type.     See  Forest  type. 

Physical  factor.  Any  inorganic  component  of  a  site  capable  of  influenc- 
ing its  forest-producing  power,  such  as  altitude,  slope,  aspect,  soil,  and 
subsoil.     See  Site. 

Physical  type.     See  Site. 

Pit  planting.     See  Forest  planting. 

Planted  forest.     See  Forest  plantation. 

Planting  area.     See  Forest  planting. 

Planting  board.     See  Transplant  board. 

Planting  plan.     See  Forest  planting  and  working  plan. 

Planting  stock.     See  Forest  planting. 

Pole.     See  Tree  class. 

Polewood.     See  Development  class. 

Pollard,  n.  A  tree  whose  crown  has  been  cut  back  to  invite  the  produc- 
tion of  shoots. 

G.,  Kopfholz.     F.,  tetard. 

Pollard,  V.  Lopping  the  top  of  a  tree  to  invite  the  production  of  shoots 
from  the  top. 

G.,  kopfen.     F.,  eteter,  ecimer. 

Possibility.     (Qhs)     See  Regulation  of  cut. 

Preparatory  cuttings.     See  Reproduction,  Shelterwood  method. 

Preparatory  stage.     See  Reproduction,  Shelterwood  method. 

Present  yield  table.     (Obs.)     See  Yield  table. 

Price  increment.     See  Increment. 

Profit.     See  Income. 

Progress  map.    See  Working  plan  control. 


APPENDIX  323 

Protection  forest.  A  forest  whose  chief  value  is  to  regulate  streamflow, 
prevent  erosion,  hold  shifting  sand,  or  exert  any  other  indirect  bene- 
ficial effect.  It  may  or  may  not  produce  timber. 
G.,  Schutzwald,  Bannwald.  F.,  foret  de  protection. 
Pruning  or  clearing,  11.  The  removal  of  branches  from  standing  trees  by 
natural  (self -pruning)  or  artificial  means.  The  clearing  of  the  stem 
through  the  death  and  fall  of  branches  for  want  of  light  is  known  as 
natural  pruning,  or  clearing  (q.  v.). 

G.,  Astreinigung.     F.,  elagage  natural. 
G.,  Aufastung;  F.,  elagage,  terms  of  artificial  pruning. 
Puddle,  n.     A  mixture  of  soil  and  water  about  the  consistency  of  cream 
in  which  the  roots  of  young  trees  are  dipped  to  retard  drying  out  during 
planting. 
Puddle,  V.     To  dip  the  roots  of  young  trees  in  a  mixture  of  soil  and  water. 
Pure  forest.     Forest  composed  principally  of  trees  of  one  species.     In 
practice  usually  a'  forest  in  which  80  per  cent  or  more  of  the  trees  are 
of  one  species. 

G.,  reiner  Bestand.     F.,  peuplement  pur. 
Quality  increment.     See  Increment. 
Quality  of  site.     See  Site  and  Site  class. 

Quality  of  stand.     The  quality  of  stand  is  its  actual  condition  from  the 
viewpoint  of  production  as  compared  with  normal  condition. 
G.,  Bestandesbonitat.     F.,  qualite  du  peuplement. 
Quincunx  planting.     See  Forest  planting. 
Range.     See  Subdivision. 
Reconnaissance.     A  preliminary,  extensive  forest  survey  of  a  limited 

degree  of  accuracy. 
Reforest,  v.     To  renew  a  forest,  either  by  natural  or  artificial  means. 
Syn.:  restock. 

G.,  aufforsten.     F.,  reboiser. 
Reforestation.     The  natural  or  artificial  restocking  of  an  area  with  forest 
trees;  most  commonly  used  in  reference  to  the  latter.     5ee  Forestation. 
G.,  Aufforstung.     F.,  reboisement. 
Regeneration,  n.     See  Reproduction. 
Regeneration  period.     See  Reproduction  period. 

Regulation  of  cut.  The  fixation  in  advance  of  the  annual  or  periodic  cut, 
which  in  the  normal  forest  would  be  equivalent  to  the  annual  growth. 
See  Cut. 


324  APPENDIX 

Syn.:  regulation  of  felling  budget;  regulation  of  yield. 

G.,  Etatsbestimmung,  Ertragsbestimmung.  F.,  fixation  de  la 
possibilite. 

The  following  classification  of  methods  of  regulating  the  cut  may  be 
recognized: 

Allotment  methods,  when  a  rotation  is  fixed  and  for  a  given  year  or 
period  of  the  rotation  a  certain  area,  a  certain  amount  of  stock,  a  cer- 
tain number  or  size  of  trees  is  allotted  to  be  cut. 

Normal  stock  or  Formula  methods,  when  the  amount  of  cut  is  deter- 
mined by  comparison  of  actual  with  normal  conditions  and  the  cut  is  in 
part  regulated  by  a  volume  formula  for  a  rotation  or  equalization 
period. 

Individualizing  or  Stand  methods,  when  each  stand  is  investigated  for 
its  financial  maturity  and  designated  for  cutting,  provided  other  age 
classes  are  in  existence  to  assure  continuity  of  crops. 
Removal  cutting.     See  Reproduction,  Shelterwood  method. 
Removal  stage.     Sec  Reproduction,  Shelterwood  method. 
Rent.     In  forest  finance,  the  income  per  acre  secured  as  an  annual  return 
from  a  forest  or  stand  under  management,  calculated  either  as  forest 
rent  or  soil  rent. 

Forest  rent  is  the  net  income  {q.  v.)  from  a  forest  organized  for  sus- 
tained yield,  without  interest  charges  on  the  forest  capital  —  book- 
keeper's balance — •  the  forest,  i.e.,  soil  with  a  stand  or  growing  stock, 
being  conceived  as  the  forest  capital,  and  the  rent  as  the  total  interest 
earned  by  it. 

G.,  Waldrente. 

Soil  rent  is  that  part  of  the  income  (or  balance)  from  a  managed  forest 
which  remains  as  interest  on  the  soil  capital  alone  after  all  expenses 
with  compound  interest  have  been  deducted,  the  soil  alone  being  con- 
ceived as  the  capital. 

G.,  Bodenrente. 
Reproduction.     1.   The  process  by  which  a  forest  is  renewed. 

Natural  reproduction  is  the  renewal  of  a  forest  by  self-sown  seeds  or 
by  sprouts.     See  also  Advance  growth. 

Syn.:  regeneration. 

G.,  natiirliche  Verjiingung.     F.,  regeneration  naturelle. 

Artificial  reproduction  is  the  renewal  of  a  forest  by  direct  seeding 
or  planting. 


APPENDIX  325 

Syn.:  reforestation. 

G.,  kiinstliche  Verjiingung.     F.,  regeneration  artificielle. 

The  collating  committee  recommends  the  use  of  plain  regeneration 
for  natural  reproduction  and  reforestation  for  artificial  reproduc- 
tion. 

2.   Seedhngs  or  saplings  from  sprouts  or  from  self-sown  seed. 

Syn.:  young  growth. 
Reproduction  cutting.     (Regeneration  cutting.)     Any  cutting  intended  to 
invite  or  assist  regeneration. 

G.,  Verjiingungshieb.     F.,  coupe  de  regeneration. 
Reproduction  method.     (Regeneration  method.)     An  orderly  procedure  or 
process  by  which  a  forest  is  renewed  or  established,  either  naturally  or 
artificially.     The  following  methods  may  be  distinguished: 

1.  Clearcutting,  with  artificial  reproduction. 

2.  Clearcutting,  with  natural  regeneration. 

3.  Seed  tree  method. 

4.  Selection. 

5.  Shelterwood. 

6.  Coppice. 

7.  Coppice  with  standards  —  Composite  forest. 

These  methods  are  defined  and  explained  as  follows: 

1.  Clearcutting  with  artificial  reproduction.  Removal  of  the  entire 
stand  in  one  cut  with  artificial  reproduction  or  reforestation  by  direct 
seeding  or  by  planting  (q.  v.).     See  also  Seed  tree  method. 

G.,  Kahlschlagwirtschaft.     F.,  methode  par  coupe  unique. 

2.  Clearcutting,  with  natural  reproduction.  Removal  of  entire  stand 
in  one  felling,  regeneration  taking  place  by  seed  from  the  marginal 
stand  or  seed  in  the  ground.  Differentiation  may  be  made  according 
to  the  form  of  felling  area  into  strip  and  group  method. 

Strip  method.  Cutting  a  strip,  and,  when  regeneration  has  taken 
place  by  marginal  seeding,  seaming  an  additional  strip  and  proceeding 
in  this  manner  from  year  to  year  or  period  to  period.  A  variant  called 
Strip  method  in  echelons  (G.,  Kulissenhieb,  Springschlag.  F.,  coupe  par 
bandes  alternes)  opens  strips  in  several  places  at  the  same  time  and 
then  proceeds  similarly  by  seaming. 

G.,  Saumhieb.     F.,  coupe  par  bandes. 

Group  method.     Proceeds  by  removing  groups  of  trees  making  more 


326  APPENDIX 

or  less  irregular  openings  and  enlarging  these  until  the  entire  stand  is 
removed. 

G.,  Kesselhieb,  Locherhieb.     F.,  coupes  par  trouees. 

3.  Seed  tree  method.  Removal  of  the  entire  stand  at  one  cut,  but 
leaving  a  small  number  of  seed  trees  singly  or  in  small  groups,  to  be 
eventually  removed.  If  the  seed  trees  are  held  over  for  another  rota- 
tion, this  may  be  called  Reserve  tree  method. 

G.,  Ueberhaltbetrieb.  F.,  traitement  en  futaie  avec  reserve  sur  coupe 
definitive. 

4.  Selection  method.  That  method  of  cutting  in  which  single  trees, 
usually  the  largest,  or  small  groups  of  such  trees,  are  removed  and 
reproduction  secured  mider  the  remaining  stand  and  in  the  openings. 
When  groups  of  trees  are  taken,  it  is  termed  Group  selection  method.  A 
special  form  of  the  selection  method  is  termed  Selection  border  felling 
or  strip  selection  (G.,  Blendersaumschlag)  when  selection  feUings  are 
made  in  narrow  strips,  in  most  instances  beginning  on  the  north 
border  and  progressing  southward,  followed  by  clear  cutting  when 
young  growth  is  fairly  established  with  the  expectation  of  additional 
marginal  seeding.     The  resulting  forest  is  uneven-aged  in  narrow  lines. 

G.,  Plenterbetrieb,  Femelbetrieb.  F.,  jardinage,  regime  de  la 
futaie  jardinee. 

6.  Sheltenvood  method.  A  method  of  securing  natural  reproduction 
under  the  temporary  shelter  of  the  seed  tree  crown  cover,  by  means  of 
a  series  of  cuttings  throughout  the  stand,  aimed  to  admit  a  gradually 
increasing  supply  of  light  to  the  seedlings.  The  principle  of  the  method 
lies  in  the  protection  (shelter)  which  the  seed  trees  (nurse  trees)  afford 
the  young  growth  during  its  youth.  The  number  and  severity  of  the 
cuttings  and  hence  the  duration  of  the  entire  removal  period,  depends 
upon  the  rate  of  establishment  and  the  need  of  light  by  the  young 
growth. 

G.,  Schirmschlagbetrieb  (Gayer  and  Lorey),  in  part  Femelschlag- 
betrieb  (Lorey).     F.,  regime  de  la  futaie  reguliere. 

In  theory  the  series  of  cuttings  is  divided  into  four  parts  as  follows: 

Preparatory  cuttings  or  fellings  fit  the  stand  for  its  reproduction 
(regeneration)  by  the  removal  of  dead,  dying,  or  defective  trees  and 
undesirable  species,  and  prepares  the  ground  for  the  seedbed  and 
encourages  seed  production.  A  stand  in  which  one  or  more  prepara- 
tory cuttings  have  been  made  is  in  the  preparatory  stage. 


APPENDIX  327 

G.,  Vorbereitungschlag.     F.,  coupe  preparatoire. 

Seed  cutting  or  Jelling.  A  further  opening  of  the  stand,  before  seed- 
ing takes  place,  to  secure  the  amount  of  hght  which  the  expected  seed- 
lings will  require.  A  stand  in  which  one  or  more  seed  cuttings  have 
been  made  is  in  the  seeding  stage. 

G.,  Besamungsschlag.     F.,  coupe  d'ensemencement. 

Removal  cuttings  or  fellings  gradually  remove  the  mature  stand, 
which  would  otherwise  retard  the  development  of  the  young  trees.  A 
stand  in  which  one  or  more  removal  cuttings  have  been  made  is  in  the 
removal  stage. 

G.,  Lichtschlag.     F.,  coupe  claire. 

The^«a/  cutting  ox  felling  is  the  last  of  the  removal  cuttings,  in  which 
all  of  the  old  stand  still  remaining  is  cut.  (G.,  Abtriebsschlag,  End- 
hieb.  F.,  coupe  definitive.)  In  practice  a  two  cut  shelterwood  method 
may  be  used,  including  the  seed  cutting  and  final  cutting  stages.  The 
shelterwood  method  may  be  applied  to  a  stand  in  narrow  strips,  from 
the  leeward  side,  at  such  intervals  that  reproduction  cuttings  are 
generally  going  on  in  three  strips  at  one  time,  one  strip  being  in  the 
removal  stage,  one  in  the  seeding  stage,  and  one  in  the  preparatory 
stage.     This  manner  of  application  is  termed  Shelterwood  strip  method. 

Another  modification  of  the  shelterwood  method  of  reproduction  is 
that  in  which  groups  of  valuable  advance  growth,  if  present,  form  the 
starting  points  for  the  cutting  which  radiates  from  these  centers.  Such 
an  application  is  termed  Shelterwood  group  method. 

6.  Coppice  method.  A  method  of  renewing  the  forest  in  which 
reproduction  is  secured  by  sprouts. 

Syn.:  sprout  method. 

G.,  Niederwaldbetrieb.     F.,  regime  du  taillis  simple. 

7.  Coppice  with  standards.  A  rhethod  of  reproduction  in  which 
seedling  trees  or  selected  sprouts  (standards)  are  maintained  above  a 
coppice  or  sprout  forest.     See  Composite  forest. 

G.,  Mittelwaldbetrieb.     F.,  regime  du  taillis. 
Reproduction  period.     The  space  of  time  required  or  normally  decided 
upon  for  the  renewal  of  a  stand  by  natural  regeneration. 
Syn.:  regeneration  period;  return  period. 
Reserve.     1.   A  tree  or  group  of  trees  left  uncut  on  an  area  for  a  period, 
usually  a  second  rotation,  after  the  stand  is  reproduced  naturally  or 
artificially.    It  may  also  refer  to  whole  stands  held  back  from  utiliza- 


328  APPENDIX 

tion.  A  tree  reserved  primarily  in  order  to  seed  the  felling  area  is 
termed  a  seed  tree.  See  Reproduction,  Seed  tree  method.  A  tree 
held  over  from  harvest  to  grow  into  or  through  a  second  rotation, 
usually  to  secure  increased  diameter  development,  may  be  termed  a 
hold-over.  A  tree  reserved  in  coppice  cutting  is  termed  a  standard.  See 
Reproduction,  Coppice  with  standards. 

2.   A  tract  of  forest  set  aside  for  forest  management. 
Syn. :  national  forest. 
Restock.     Sec  Reforest. 

Revision  of  working  plan.  The  rewriting  of  a  working  plan  at  the  end  of, 
or  during  the  working  period.  Such  renewals  may  be  made  at  fixed 
intervals  of,  say,  lo  years,  or  at  irregular  intervals,  as  is  commonly  the 
case  where  revised  data  or  changes  in  prevailing  market  conditions, 
etc.,  necessitate  modification  of  the  original  plan. 
Ride.  A  term  used  in  EngHsh  literature  for  opened  up  division  lines 
between  compartments. 

G.,  Schneisse,  Gestell.     F.,  laie. 
Ripe.     See  Mature  forest. 
Root  sucker.     A  sprout  from  a  root. 

Rotation.  The  predetermined  time  period  during  which  it  is  intended  to 
cut  over  a  working  group;  the  predetermined,  approximate  felling  age 
of  stands.  Rotation  refers  to  the  forest  as  a  whole  and  is  expressed 
not  by  a  definite  year,  but  a  period  of  lo  to  20  years;  Jelling  age  refers 
to  a  stand  and  a  definite  year. 

Rotations  are  determined  either  by  technical,  economic,  or  financial 
considerations;  silvicultural  considerations  exercising  a  hmiting 
influence. 

Technical  rotations  attempt  to  produce  the  maximum  amount  of 
material  suitable  for  a  certain  purpose,  such  as  railroad  ties,  mine 
timbers,  saw  logs  of  given  size. 

Economic  rotations  attempt  to  secure  either  the  maximum  average 
volume  production,  or  the  maximum  average  value  production. 

Financial  rotations  introduce  considerations  of  cost  and  attempt  to 
secure  either  the  maximum  forest  rent  or  maximum  soil  rent  {q.  v.). 
Syn.:  income  rotation. 
G.,  Umtrieb,  Turnus.     F.,  revolution. 
Row  planting.     See  Forest  planting. 
Sale  value.    See  Value. 


APPENDIX  329 

Salvage  felling.     {New  term.)     Removal  of  trees  killed  or  injured  in  a 
forest  by  fire,  insects,  fungi,  or  other  harmful  agencies,  with  the  purpose 
of  utilizing  merchantable  material  and  preventing  the  spread  of  insects 
and  disease.     See  under  Intermediate  fellings. 
G.,  Totalitatshieb.     F.,  coupe  accidentelle. 

Sample  plot.  A  sample  plot  is  an  accurately  measured  area  used  for  pur- 
poses of  experimentation  or  of  mensuration.  Sample  plots  may  be 
either  permanent  or  temporary. 

Sample  tree.     See  Mean  sample  tree. 

Sapling.     See  Tree  class. 

Scale,  n.  The  contents  of  a  log  or  logs  as  determined  by  measurement 
with  a  scale  stick. 

Scale,  1).  To  determine  the  contents  of  a  log  by  measurement  with  a 
scale  stick. 

Scale  rule.     See  Scale  stick. 

Scale  stick.  A  stick  usually  graduated  to  inches,  showing  for  logs  of 
different  diameters  and  lengths  the  corresponding  contents  in  board 
feet  or  other  unit  according  to  a  given  log  rule  {see  Log  rule). 

Screen.     See  Shade  frame. 

Scribe.    A  tool  designed  for  carving  symbols  in  wood  or  bark,  commonly 
used  to  mark  lines  or  corner  posts. 
Syn. :  timber  scribe,  tree  scribe. 

Second  growth.  Forest  growth  which  comes  up  naturally  after  cutting, 
fire,  or  other  disturbing  cause.  In  lumberman's  parlance,  the  smaller 
trees  left  after  lumbering  or  the  available  trees  for  a  second  logging. 
See  Old  growth. 

Seedbed.  1.  In  natural  reproduction  the  soil  or  forest  floor  on  which 
seed  falls. 

2.   In  nursery  practice,  a  subdivision  of  a  nursery  for  the  raising  of 
seedlings. 

G.,  saatbeet.     F.,  couche  de  semis. 

Seed  board.     See  Forest  planting. 

Seed  cutting  or  felling.     See  Reproduction  (Shelterwood)  method. 

Seed  drill.     See  Forest  planting. 

Seed  forest.     See  High  forest. 

Seed  horn.     See  Forest  planting. 

Seed  spot.  A  prepared  spot  usually  about  a  foot  square  in  which  tree 
seeds  are  to  be  planted. 


330  APPENDIX 

Seed  spot  method.     See  Direct  seeding. 

Seed  tree.  Any  tree  which  bears  seed;  specifically,  a  tree  which  is  to 
provide  the  seed  for  natural  reproduction. 

Syn.:  mother  tree;  nurse  tree. 

G.,  Mutterbaum,  Samenbaum.     F.,  portegraine,  semencier. 
Seed  tree  method.     See  Reproduction,  method  of. 
Seed  year.     A  year  in  which  a  given  species  bears  seed  abundantly. 

G.,  Samenjahr.     F.,  annee  de  semence. 
Seeding.     See  Direct  seeding. 
Seeding  stage.     See  Shelterwood  method. 
SeedUng.     1.   A  tree  grown  from  seed. 

G.,  Kernwuchs.     F.,  brin  de  semence. 

2.  In  nursery  practice,  a  tree  which  has  not  been  transplanted  in  the 
nursery.    See  Planting  stock. 

3.  In  natural  reproduction,  a  tree  from  seed  which  has  not  reached 
a  height  of  3  feet.    See  Tree  class. 

G.,  Samling,  Keimling.     F.,  jeune  brin. 

Seedling  forest.     See  High  forest. 

Seedling  sprout.  A  sprout  resulting  from  the  cutting  of  a  seedling  or 
small  saphng.  This  is  differentiated  from  coppice  sprout  or  shoot 
because  of  its  subsequent  behavior. 

Selection  forest.  A  forest  through  all  parts  of  which  many,  or  theoreti- 
cally all  age  classes  are  represented. 

Selection  method.     See  Reproduction  method. 

Selection  thinning.     See  Intermediate  cuttings. 

Self  pruning.     See  Pruning  and  Clear. 

Self-sown  seed.     Seed  sown  by  any  agency  other  than  man. 

Set  free,  v.     See  Intermediate  (liberation)  cuttings. 

Severance  felling  or  cutting.     See  under  Intermediate  cuttings  or  feUing. 

Shade  enduring.     See  Tolerant. 

Shade  frame.  A  frame  for  the  partial  shading  of  a  seedbed.  It  consists 
of  a  cover  of  laths,  brush,  or  cloth,  arranged  so  that  light  can  be  ad- 
mitted as  desired  and  is  frequently  used  in  combination  with  a  frame 
and  cover  provided  with  wire  netting  to  keep  out  birds  and  rodents. 

Shaft.    See  Stem. 

Shelterbelt.     See  Windbreak. 

Shelter  growth.  An  advanced  growth  used  to  protect  shade-demanding 
species.    A  new  term  to  designate  nurse  trees  collectively. 


APPENDIX  331 

Shelterwood  method.     See  Reproduction  method. 
Shoot.     See  Tree  class. 
Silvical.     Pertaining  to  silvics. 

Silvics.  1.  A  branch  of  ecology  that  treats  of  the  life  of  trees  in  the 
forest;  forest  ecology. 

2.   The  life  history,  requirements,  and  general  characteristics  of  a 
forest  tree  from  the  point  of  view  of  silviculture. 
Silvicultural  characteristics.     See  Silvics  (2). 

Silviculture.     The  art  of  producing  and  tending  a  forest ;  the  application 
of  the  knowledge  of  silvics  in  the  treatment  of  a  forest. 
G.,  Waldbau,  Holzzucht.     F.,  Sylviculture. 
Single  tree  method.     (Obs.)     See  Reproduction  (Selection)  method. 
Site,     An  area,  considered  as  to  its  physical  factors  with  reference  to 
forest  producing  power;  the  combination  of  climatic  and  soil  conditions 
of  an  area.     See  Site  class. 
Syn. :  locality,  physical  type. 
G.,  Standort.     F.,  station. 
Site  class.     A  designation  of  the  relative  productive  capacity  or  quahty 
of  different  sites  with  reference  to  the  species  employed;   the  volume 
or  the  height  produced  at  a  given  age  being  used  as  standard  for  classi- 
fication.    In  Europe  five  classes,  in  the  United  States  often  only  three 
classes  are  differentiated,  designated  by  Roman  numerals,  quality  I 
representing  the  most  productive  site  class. 
Syn.:  quality  of  site. 
G.,  Bonitat.     F.,  qualite  du  sol. 
Slit  method.     See  Forest  planting. 

Slope.  The  gradient  of  the  land  surface.  In  forest  description,  the  fol- 
lowing terms  are  used  to  define  the  slope,  each  of  which  has  its  equiva- 
lent in  percentages  of  the  horizontal  distance  and  in  degrees: 


Level 

= 

0- 

■     5%  = 

0- 

-  3° 

Gentle 

= 

s- 

■15%  = 

3- 

-8° 

Moderate 

= 

15- 

•30%  = 

8- 

-16° 

Steep 

= 

30- 

■So%  = 

16-26° 

Very  steep 

= 

5°- 

100%  = 

26- 

■45° 

Precipitous 

= 

over 

100%  = 

over  45* 

Snowbreak.     The  breaking  of  limbs  of  trees  by  snow. 
G.,  Schneebruch.     F.,  bris  de  neige. 


332  APPENDIX 

Social.     Said  of  species  apt  to  form  pure  stands. 
Syn.:  gregarious. 

Soil.  In  forest  description,  the  origin,  composition,  depth  and  moisture 
of  the  forest  soil  are  considered  under  soil.  Its  depth,  to  subsoil,  rock 
or  groundwater,  is  defined  by  the  following  terms,  each  of  which  has 
its  equivalent  in  inches: 

Very  shallow  =  less  than  6  inches. 
Shallow  =    6  to  12  inches. 

Moderate        =  1 2  to  24  inches. 
Deep  =  24  to  36  inches. 

Very  deep       =  over  36  inches. 

The  moisture  of  the  soil  is  defined  by  the  following  terms: 

Wet.  When  water  drips  from  a  piece  held  in  the  hand  without 
pressing. 

Moist.     When  water  drips  from  a  piece  pressed  in  the  hand. 

Fresh.  When  no  water  drips  from  a  piece  pressed  in  the  hand, 
though  it  is  unmistakably  present. 

Dry.     When  there  is  httle  or  no  trace  of  water. 

Very  dry.  When  the  soil  is  parched.  Such  soils  are  usually  caked 
and  very  hard,  sand  being  an  exception. 

Soil  rent.     See  Rent. 

Soil  rent  value.     Value  based  on  soil  rent. 

Sour  humus.     See  Humus. 

Sowing.     See  Direct  seeding. 

Space  number.     The  average  distance  between  the  trees  in  a  stand 

divided  by  their  average  diameter;  used  to  estimate  volume  of  stand. 
G.,  Abstandszahl. 
Sprout.     A  tree  which  has  grown  from  a  stump  or  root.     See  Tree  class. 
Syn.:  shoot,  root  sucker. 
G.,  Stockausschlag.     F.,  rejet  de  souche. 
Sprout  forest.     See  Coppice. 
Sprout  method.     See  Reproduction  methods. 
Stagheaded.     A  term  applied  to  a  tree  dead  at  the  top  as  a  result  of  injury, 

disease,  or  deficient  moisture  and  nutriment. 
Stand.     A  general  descriptive  term  referring  to  an  aggregation  of  trees, 

standing  on  a  limited  area,  of  more  or  less  uniformity  of  composition 

and  condition,  or  of  age. 


APPENDIX  333 

G.,  Bestand.     F.,  peuplement. 

In  mensuration,  the  amount  of  material  on  a  given  area:   usually- 
expressed  in  terms  of  Stand  per  acre. 
Syn. :  growing  stock. 

Stand  quality.     See  Quality  of  stand. 

Stand  table.  A  tabular  enumeration  showing  separately  for  each 
diameter  class  and  species,  the  number  of  trees  on  a  given  unit  of  area, 
usually  an  average  acre.  The  corresponding  volume  may  or  may  not 
be  given.     If  given,  the  table  may  be  called  Stock  table  (q.  v.). 

Standard.     1.   See  Tree  class  (in  reference  to  size  classification) . 

2.   A  seedhng  or  selected  healthy  sprout  in  a  coppice  forest  left  uncut 
to  grow  for  more  than  one  rotation.     See  Reserve. 

Status  records.  An  administrative  term  for  records  showing  the  owner- 
ship of  lands.  Complete  status  records  will  show  in  detail  the  chain 
of  title  for  each  parcel  of  land  and  also  for  all  servitudes  and  easements 
attached  to  the  land.  In  addition,  they  usually  show  the  location  and 
extent  of  all  quaUfied  or  temporary  aUenations,  such  as  unpatented 
mineral  claims,  leased  areas,  or  lands  otherwise  specifically  under  per- 
mit or  affected  by  outstanding  contracts,  as  for  the  sale  of  timber,  etc. 
Status  records  usually  consist-  of  sets  of  maps,  often  called  "  tract 
books  "  and  of  written  or  tabulated  records  supplemental  to  the  map 
records. 

Stem.  The  trunk  of  a  tree.  The  stem  may  extend  to  the  top  of  the  tree, 
as  in  some  conifers,  or  it  may  be  lost  in  the  ramification  of  the  crown, 
as  in  most  broadleaf  trees.  In  tree  description,  the  stem  is  described 
as  long  or  short,  straight  or  crooked,  cylindrical  or  tapering,  smooth  or 
knotty,  clear  or  rough,  etc.  The  synonym  bole  may  be  suitably 
reserved  when  speaking  from  the  standpoint  of  utilization,  using  stem 
or  shaft  from  the  standpoint  of  mensuration,  stem  or  trunk  for  descrip- 
tion merely. 

Syn.:  trunk,  bole,  shaft. 

Stem  analysis.  The  measurement  of  stated  cross  sections  of  a  tree 
to  determine  its  increment  at  different  periods  of  its  life.  A  stem 
analysis  may  be  either  partial  or  complete  depending  on  whether  the 
measurements  include  only  a  portion  or  all  of  the  stem. 

Stem  class.     See  Tree  class. 

Stem  density.     See  Stock  density. 

Stem  form  factor.     See  Form  factor. 


334 


APPENDIX 


Stock,   n.     1.   The    stump    of    a    coppice    from    which    sprouts    are 
expected. 

2.     A  general  term  used  to  describe  the  character  of  the  forest  cover 
in  composition  or  condition  or  supply  of  material  (stumpage). 

In  organization,  growing  stock,  the  volume  of  material  present,  as 
basis  of  management;   in  finance,  the  value  or  capital  represented  in 
the  stumpage  of  a  stand  or  forest.     See  Normal  stock.     Undesirably 
used  as  synonym  for  Stand. 
Stock  density.     Expressed  by  reference  to  number  of  trees  or  total  basal 
area  per  acre,  three  grades  being  recognized:  dense,  medium,  open. 
G.,  Bestandesdichte.     F.,  consistance. 
Stock  map.     A  map  giving  by  symbols  and  numbers  the  composition  of 

a  stand  or  forest. 
Stock  table.     See  Stand  table.     A  table  enumerating  the  volume  of  a 

stand  by  tree  classes. 
Stock-taking.     See  Forest  survey. 
Stool  shoot.     A  sprout  from  a  stump. 
Stoutwood.     See  Assortment. 
Stratify.     In  nursery  and  planting  practice,  to  preserve  tree  seeds  by 

spreading  them  in  layers  alternating  with  layers  of  earth  or  sand. 
Strip  method.     See  Reproduction,  clearcutting  method  and  shelterwood 

method. 
Strip  selection  method.     See  Reproduction  (Selection)  method. 
Strip  seeding  method.     See  Direct  seeding. 

Strip  survey.     A  partial  survey;   more  precisely  a  process  of  estimating 

timber  by  measuring  it  on  strips  laid  out  over  the  area  to  be  surveyed 

according  to  a  systematic  scheme  {see  Forest  survey)  and  applying  the 

measurements  to  the  whole  area  in  proportion. 

Stub.     That  portion  of  the  trunk  left  standing  when  a  tree  is  accidentally 

broken  off. 
Stump.     That  portion  of  the  trunk  below  the  cut  made  in  felling  a  tree. 

G.,  Stock.     F.,  souche. 
Stump  analysis,     A  partial  stem  analysis  in  which  the  only  section  used 

is  the  surface  of  the  stump.     See  Stem  analysis. 
Stump  height.     The  average  distance  between  the  juncture  of  the  stem 

and  roots  (root  collar)  and  the  surface  of  a  stump. 
Stumpage,     1,  Amount  of  saleable  material  in  a  stand. 
Syn.:  stock. 


APPENDIX  335 

2.  Stumpage  value,  the  value  of  timber  as  it  stands — "on  the 
stump."     May  include  all  wood  or  only  certain  classes. 

3.  Price  paid  for  standing  timber. 
Subcompartment.     See  Subdivision. 

Subdivision.  A  larger  or  smaller  part  of  a  forest  property  segregated 
with  a  view  to  making  units  for  purposes  of  administration,  protection, 
organization,  management. 

District.  Generically,  any  administrative  unit;  specifically,  an 
aggregate  of  administrative  units  or  forests  for  control  and  inspection 
purposes. 

Forest.  An  administrative  unit,  as  National  forest.  State  forest, 
Municipal  forest. 

Ranger  district  or  Range.  Part  of  a  forest,  an  executive  unit  under 
care  of  a  ranger. 

Patrol  district  or  Beat.  An  executive  unit  for  protective  purposes, 
under  a  guard  or  patrol. 

Compartment.  An  organization  unit  or  small  subdivision  for  pur- 
poses of  orientation,  administrative,  and  silvicultural  operations. 

G.,  Abteilung,  Jagen  (Prussia). 

Lot.  A  small  subdivision  of  a  compartment,  differing  in  composition, 
age,  or  character,  requiring  different  treatment  from  the  main  body  of 
the  compartment;  impermanent  if  due  to  accidental,  permanent  if  due 
to  site  conditions. 

Syn.:  subcompartment. 

G.,  Unterabteilung,  Abteilung  (Prussia). 

Block.  A  major  division  of  the  working  plan  unit,  intermediate  in 
size  between  the  working  plan  unit  and  a  compartment.  A  block  is 
usually  based  on  topography  and  comprises  a  main  logging  unit  or 
group  of  logging  units.  A  single  block  may  contain  many  thousand 
acres. 

Working  plan  unit.  A  forest  area  managed  under  one  working  plan. 
It  may  or  may  not  coincide  with  the  administrative  unit. 

G.,  Wirtschaftsganzes. 

Working  group.  An  organization  or  working  plan  unit,  comprising 
an  aggregate  of  compartments  or  stands  to  be  managed  under  the  same 
silvicultural  system  and  rotation. 

Syn.:  working  block ;  working  circle;  working  figure;  working  sec- 
tion; management  class. 


336  APPENDIX 

G.,  Betriebsklasse.     F.,  Serie  d'exploitation. 
Sublet.     See  Subdivision. 

Suppressed,  a.     Having  growth  seriously  retarded  by  shade,  dying  or  so 
far  injured  that  recovery  is  not  probable.     See  also  Crown  class. 
G.,  unterdriickt.     F.,  domine. 
Sustained  annual  yield.     See  Sustained  yield. 
Sustained  periodic  yield.     Sec  Sustained  yield. 

Sustained  yield.     The  yield  or  cut  of  timber  from  a  forest  which  is  man- 
aged in  such  a  way  as  to  permit  the  removal  of  an  approximately  equal 
volume  of  timber  armually  or  periodically,  equal  to  the  increment. 
Taper.    The  gradual  diminution  of  diameter  in  the  stem  of  a  tree  from 

base  to  top. 
Taper  table.    A  tabular  statement  of  average  diameter  measurements  of 
stems  at  specified  heights  above  ground,  recorded  for  trees  of  varying 
d.  b.  h.  and  height  classes.     Used  for  determining  volumes  and  dimen- 
sions of  products. 
Thicket.     A  stand  of  saplings.     See  Development  class. 

G.,  Dickicht.     F.,  fourre. 
Thin,  V.     To  make  a  thinning. 
Thinning.     See  Intermediate  cuttings. 
Timber  forest.     See  High  forest. 
Timberland.     See  under  Forest. 
Timber  form  factor.    See  Merchantable  form  factor. 
Timber  scribe.     See  Scribe. 
Timberwood.     See  Assortment. 
Tolerance.    The  capacity  of  a  tree  to  endure  shade. 
Tolerant.     Capable  of  enduring  more  or  less  heavy  shade. 
Syn.:  shade-bearing,  shade-enduring. 
G.,  Schattenertragend.     F.,  a  temperament  delicat. 
Transition  period.    The  time  used  in  bringing  an  unorganized  forest  into 
sustained  yield  management. 

G.,  Uebergangszeitraum.     F.,  periode  de  transition. 
Transplant,  v.     To  transfer  seedlings  from  the  seedbed  and  set  them  in 
the  ground  in  another  part  of  the  forest  nursery. 
G.,  verpflanzen,  verschulen.     F.,  transplanter. 
Transplant,  n.    A  seedling  which  has  been  transplanted  one  or  more 
times  in  the  nursery.     See  Planting  stock. 

G.,  Schulpflanze.     F.,  plant  repique,  plant  rigolee. 


APPENDIX 


337 


Transplant  board.  An  implement  used  in  setting  seedlings  in  transplant 
rows  or  beds.  The  principle  of  the  tool  is  a  device  which  holds  the  trees 
in  place  in  a  notched  board  so  that  a  number  may  be  planted  at  a  time. 

Trap  tree.  A  tree  felled  or  girdled  for  the  purpose  of  collecting  injurious 
insects. 

Tree  analysis.     See  Stem  analysis. 

Tree  class.  All  trees  of  approximately  the  same  size.  The  following 
tree  classes  are  distinguished: 

Seedling.     A  tree,  grown  from  seed,  not  yet  3  feet  high. 
Shoot.     A  sprout,  not  yet  3  feet  high. 
Small  sapling.     A  tree  from  3  to  10  feet  high. 

Large  sapling.     A  tree  10  feet  or  over  in  height  and  less  than  4  inches 
d.  b.  h. 
Small  pole.     A  tree  from  4  to  8  inches  d.  b.  h. 
Large  pole.     A  tree  from  8  to  12  inches  d.  b.  h. 
Standard.     A  tree  from  i  to  2  feet  d.  b.  h. 
Veteran.     A  tree  over  2  feet  d.  b.  h. 
See  also  Development  class. 

Tree  compass.  An  instrument  for  measuring  diameter,  consisting  of  a 
pair  of  dividers  and  a  scale  bar. 

Tree  form  factor.     See  Form  factor. 

Tree  scribe.     See  Scribe. 

Tree  tape.     See  Diameter  tape. 

Trench  planting.     See  Forest  planting. 

Trench  sowing.     See  Direct  seeding. 

Trunk.     See  Stem. 

Turnus.     See  Rotation. 

Two-storied  forest.  A  stand  in  which  two  height  or  age  classes  of  con- 
siderable difTerence,  usually,  are  developed  or  are  intended  to  be  main- 
tained, as  upper  story  or  overwood  and  lower  story  or  underwood. 
The  term  is  not  applicable  to  forest  under  reproduction,  in  which  the 
appearance  of  two  stories  is  the  temporary  result  of  an  incomplete 
process,  but  to  those  forests  of  which  the  two  stories  of  growth  are  a 
permanent  feature. 

G.,  Zweihiebig.     F.,  a  double  etage. 

Underbrush.  All  large  woody  plants,  which  grow  in  a  forest,  but  do  not 
make  trees. 


338  APPENDIX 

Under-cut.     In  forest  management  the  cutting  of  a  quantity  of  timber 
less  than  the  annual  growth  of  the  forest  or  the  predetermined  amiual 
cut.     See  also  Lumber  manufacturing  terms. 
Undergrowth.     A  term  used  to  include  underbrush,  seedlings,  shoots,  and 

small  saplings. 
Underplant.     To  set  out  young  trees  or  sow  seeds  under  an  existing  stand. 
Under-stock.     A  growing  stock  less  than  the  normal  growing  stock. 
Underwood.     See  Composite  forest. 

Uneven-aged.     Applied   to   a   stand   or   forest   in   which   considerable 
differences  in  age  of  trees  occur,  differences  varying  with  the  average 
age  of  stand  or  forest.     See  Even-aged;  Selection  forest. 
G.,  ungleichalteriger  Bestand.     F.,  peuplement  mele. 
Unit  of  regulation.     See  Subdivision,  Working  unit. 
Used  length.     The  total  length  of  stem  usable  in  commercial  operations. 
Used  volume.     The  volume  of  that  portion  of  the  tree  usable  in  commer- 
cial operations. 
Utilization  value.     See  Value. 

Valuation   survey.     The  survey  of  an  average  area   (valuation  area) 
selected  for  detailed  measurement  and  valuation.     Often  objectionably 
used  for  mensuration  areas  when  no  valuation  is  involved  but  only 
material  is  measured. 
Value.     The  following  values  may  be  differentiated. 

Investment  value.     The  purchase  price  or  the  actual  expenditures  or 
investments  that  have  been  made  in  acqiiiring  or  creating  the  property 
with  interest,  less  incomes  actually  derived  from  it,  with  interest. 
G.,  Anlagekapitalwert. 

Cost  value.     An  investment  value  based  on  production.     This  may 
be  differentiated  into  Subjective  cost  value  if  based  on  actual  expendi- 
tures, and  Objective  cost  value  if  based  on  estimated  cost  of  replacement 
of  the  property  (as  in  damage  suits) . 
G.,  Kostenwert. 

Sale  or  Exchange  value.  The  market  price  based  on  statistics  of 
actual  sales;  a  special  kind  of  sale  value  is  the  forced  sale  or  wrecking 
value  that  can  be  obtained  by  exploitation  of  saleable  parts  {see  Stump- 
age  value). 

G.,  Verkaufswert.     F.,  valeur  venale. 

Stock  or  Stumpage  value.  Based  on  sale  value  of  material  ready  for 
immediate  utilization. 


APPENDIX  339 

Syn. :  utilization  value. 
G.,  Nutzungswert. 

Expectancy  value.  The  present  worth  of  all  estimated  or  expected 
future  net  earnings  (discounted  value);  the  capitalized  net  income 
value. 

G.,  Erwartungswert.     F.,  valeur  d'attente. 

Rent  or  Yield  value.  A  value,  determined  by  capitalizing,  with  a 
demanded  rate  of  interest,  the  yearly  or  intermittent  net  return  pos- 
sible to  be  derived  from  a  managed  property.  See  Forest  rent  and  Soil 
rent. 

G.,  Bodenrentierungswert;  Waldrentierungswert. 
Value  increment.     See  Increment. 
Veteran.     See  Tree  class. 

Virgin  forest.     Applies  to  mature  or  overmature  forest  grown  entirely 
uninfluenced  by  human  activity. 
Syn.:  old  growth. 
G.,  Urwald.     F.,  foret  vierge. 
Volume  table.     A  tabular  statement  showing,  for  a  given  species,  the 
average  contents  of  trees  of  different  sizes.     The  usual  volume  table  is 
based  on  diameter  and  height.     Volume  tables  may  be  made  for  any 
desired  unit  of  volume. 
Volunteer  growth.     See  Advance  growth. 

Water  sprout.     An  epicormic  branch  arising  from  a  dormant  or  adven- 
titious bud. 
Weed  tree.     A  tree  of  a  species  which  has  little  or  no  value. 
Weeding.     See  Intermediate  cuttings,  cleanings. 

Windbreak.  Any  object  which  serves  as  an  obstacle  to  surface  winds; 
in  forestry  trees  serve  such  a  purpose.  Tree  windbreaks  are  classified 
according  to  their  general  arrangement. 

1.  Rows  and  hedge  rows;  2.  belts  or  shelterbelts  of  three  or  more 
rows;  3.  groves,  or  in  the  most  extensive  case,  forests.  They  may  be 
of  natural  or  artificial  origin. 

Windfall.     1.   A  tree  thrown  by  wind. 

2.  An  area  on  which  the  trees  have  been  thrown  by  wind. 
Syn.:  windbreak,  blow-down. 

G.,  Windbruch.     F.,  volis. 
Wind-firm.     Able  to  withstand  heavy  wind. 

G.,  sturmfest,  windfest.     F.,  resistant  au  vent. 


340  APPENDIX 

"Wind  mantle.  A  screen'  of  trees,  commonly  used  to  designate  the  dense 
border  of  a  woodlot  or  forest  which  prevents  penetration  of  wind  into 
the  interior. 

G.,  Waldmantel. 

Wolf  tree.  A  tree  occupying  more  space  than  its  silvicultural  value 
warrants,  curtailing  better  neighbors.  A  term  usually  applied  to  broad- 
crowned,  short-stemmed  reserves. 

Woodland.     See  Forest. 

Woodlot.     See  Forest. 

Working  block.     See  Subdivision. 

Working  capital.     See  Capital. 

Working  circle.     See  Subdivision. 

Working  figure.     See  Subdivision. 

Working  period.  The  period  of  years  during  which  the  working  plan  is 
intended  to  apply. 

Working  plan.  The  plan  or  plans  under  which  a  given  forest  property  is 
to  be  continuously  managed.  Annual  or  Periodic  plans  may  be  based 
on  the  general  working  plan  and  may  refer  to  any  specified  class  of 
work,  as  the  annual  cutting  or  felling,  planting,  protection,  grazing,  or 
administration  and  improvement  plan.  Such  annual  plans  may  be 
either  mere  schedules  or  may  contain  more  or  less  detail,  explanations, 
estimates  of  cost  and  results,  as  seems  desirable. 

Working  plan  control.  The  records  of  the  progress  of  the  work  on  the 
forest  as  outlined  by  the  working  plan.  In  European  practice  these 
records  are  kept  by  maps  and  books.  The  entries  are  made  periodi- 
cally or  at  the  time  of  completing  each  of  the  various  projects.  This 
control  operates  as  a  check  on  the  execution  of  the  working  plan. 

Working  section.     See  Subdivision. 

Working  unit.     See  Subdivision, 

Yield.  The  timber  or  wood  volume  that  is  (actually)  or  can  be  (nor- 
mally) produced  by  a  stand  of  a  given  composition  at  a  given  age  under 
given  site  conditions  and  treatment  —  the  actual  or  normal  product  of 
the  stand.  See  Normal.  In  finance,  may  be  expressed  as  money  yield. 
The  term  Yield  involves  the  idea  of  futurity,  hence  for  a  statement 
of  actual  material  on  hand  the  term  Stock  is  preferable.  For  the  ex- 
pression Regidation  of  yield,  the  expression  Regulation  of  cut  or  of 
felling  budget  is  preferred. 

Yield  table.     A  tabular  statement  of  periodic  yields  attainable  at  differ- 


APPENDIX  341 

ent  ages  (usually  in  lo-year  periods)  per  unit  of  area  (usually  per 
acre) . 

Normal  yield  tables  are  constructed  separately  for  given  species  on 
different  sites  (and  sometimes  different  growth  regions)  under  different 
treatment,  and  are  used  as  standards  with  which  to  compare  actual 
yields.  The  statements  of  a  normal  yield  table  are  derived  as  an 
average  from  the  best  producing  areas.  If  a  normal  forest  were  not 
only  an  idea,  but  actually  attainable,  the  normal  yield  table  would 
represent  its  productivity  and  stock. 

Empirical  yield  table  is  a  statement  of  the  actual  volumes  of  given 
stands.  They  are  of  local  value  only.  Since  there  is  no  "  experience  " 
involved,  the  term  Local  yield  table  would  be  preferable. 

In  finance,  volumes  may  be  translated  into  values  and  referred  to  as 
money  yield  table,  income  table,  or  financial  yield  table. 

G.,  Wald-  or  Forstertrag;  Materialertrag;  Geldertrag.  F.,  rende- 
ment. 


fSOPEJnr  linn  A  fir 

V.C 


INDEX 


Abnormal  needle  shedding,  279 
Accretion  cutting,  163,  171 
Administration,  cost  of,  10 
Advance  growth,  64,  71,  146 
Adventitious  buds,  iii 
Esthetic  effects,  5,  41,  56,  78,  80,  103, 
108,  123,  137 

slash  in  relation  to,  219 
Age  classes,  84,  91,  107,  128,  134 
Agriculture,  2 
All-aged,  84 
Animals,  protection  against,  293 

beaver,  293 

birds,  294 

deer,  293 

mice,  294 

porcupines,  293 

rabbits,  294 

squirrels,  294 
Appendix,  299 

Artificial  reproduction,  ^Sj  36,  40,  55, 
63,  102,  116,  132 

advantages  of,  19 

compared  with  natural,  18  to  22 

definition  of,  19 

opportunities  for  applying,  22 
Ash,  white,  138 
Ashe,  W.  W.,  95 
Aspen,  293 
Assimilation,  60 
Assistance  cutting,  142 
Avalanches,  protection  against,  296 

Baden,  136 
Balsam,  eastern,  80 
Bark-scorching,  279 


Barnes,  W.  C,  289 

Basal  area,  161,  172 

Basket  wiUow,  125 

Beaver,  protection  against,  293 

Birch,  D.  C,  8 

Birds,  protection  against,  294 

Black  HiUs,  80 

Blister  rust,  white  pine,  277,  278 

Border  cuttings,  70 

Borggreve,  177 

Borggreve's  method  of  thinning,  162, 

177,  188 
Broadcast  burning,  29,  223,  229,  230, 

231,  233 
Brush,  disposal  of,  25,  29,  49,  116 
Burning,  broadcast,  29,  223,  229,  230, 

231,  233 

Caccia,  A.  M.  F.,  95 
Cambium,  temperature  to  kill,  244 
Causes  of  fires,  260 
Chestnut,  113,  275 
Chestnut  blight,  275,  277,  278,  280 
Chir  pine,  228 

Cleanings,  30,  142,  144,  159,  192,  2c8 
Clearcutting,  14, 15,  23,  25,  57,  77,  79, 
107,  108, 117 

advantages,  40 

application  of,  41,  297 

definition,  25 

details  of  method,  25 

disadvantages,  40 

in  alternate  strips,  32 

in  one  operation,  32 

in  patches,  37 

in  progressive  strips,  35 


PROPERTY  LIBRARY 
N.  C.  State  Colkgi 


344 


INDEX 


Clearcutting,  in  strips,  32 

in  two  or  more  operations,  32,  35, 
38,56 

marking  for,  207 

modifications  of  the  method,  32 

slash  disposal  for,  224,  229 

the  whole  stand,  32,  100 

with  artificial  reproduction,  25 

with  natural  reproduction,  25,  26, 
56 
Clearings,  location,  31,  34 

size,  31,  41 

width,  30 
Climbing  vines,  147 
Co-dominant  trees,  47,  63,  64,   134, 
146,   156,   162,   163,   172,   17s, 
177 
Compartment  method,  59 
Compound  coppice,  127,  136 

three  kinds,  133 
Conky  trees,  48 
Control  of  cuttings,  204 

through  inspection,  204,  213 

through  marking,  205 
Conversion  into  high  forest  of  cop- 
pice and  coppice  with  stand- 
ards, 139 
Coppice  forest  methods,  1 5 
Coppice  method,  in,  127,  136,  137, 
138 

advantages,  121 

application  of,  123 

conversion  into  high  forest,  139 

definition,  in 

details  of,  in 

disadvantages,  122 

marking,  207 

modification  of,  117 

slash  disposal  for,  231 
Coppice  with  standards,  advantages, 
136 

application  of,  138,  297 


Coppice,  conversion  into  high  forest, 

139 

definition  of,  127 

details  of,  127 

disadvantages,  137 

marking,  207 

method,  127 

modification  of,  136 

slash  disposal  for,  231 
Costs,  due  to  making  the  investment 
a  permanent  one,  10 

of  administration,  10 

of  logging,  8,  9,  79 

of  lopping,  226 

of  marking,  207 

of  protection,  9 

of  pruning,  202,  203 

of  reproduction,  9 

of  silviculture,  7 

of  slash  disposal,  233 
Cottonwood,  49,  58,  154 
Cox,  Wm.  T.,  234 

Crown  classes,  basis  for  selecting  trees 
in  thinning,  160,  161 

classification  into,  154 

differentiation  into,  159 

relative   position   of   trees   of  the 
different,  155 

standard,  155 
Crown  fire,  250,  257 
Cuttings,  accretion,  163,  171 

assistance,  142 

cleaning,  30,  142,  144,  159,  208 

clearcutting,  25,  229 

damage,  194 

disengagement,  142 

improvement,   142,    143,   144,  192, 
208 

interlucation,  163,  171 

intermediate,  6,  102,  141,  153,  192, 
208,  210,  231 

liberation,  142,  143,  144,  149,  159, 
208,  232 


INDEX 


345 


Cuttings,  methods  of  controlling,  204 

partial,  59 

preparator}',  60,  63,  68,  76,  80 

primary,  71,  74 

priming,  143,  198,  208 

release,  142 

removal,  60,  64,  68 

reproduction,  6,  139,  172,  178,  195, 
207,  210,  229 

salvage,  142,  143,  144,  194,  208 

secondar>',  71 

seed,  60,  68,  71,  76,  80,  117 

selection,  83,  107 

severance,  143,  195,  208,  261 

shelterwood,  60 

thinning,  142,  144,  208 

weeding,  142 
Cutting  cycle,  77,  81,  87,  91,  100 
Cutting  series,  36,  69,  70 

Damage  cutting,  194 
Deep  rooted  species,  57     • 
Deer,  protection  against,  293 
Density  of  stocking,  3 
Diameter  growth,  105,  157,  171 
Diameter  Umit,  92 
Dioecious,  49 

Disengagement  cutting,  142 
Dispersal  of  seed,  27,  28,  29,  52 
Disposal  of  slash,  25,  29,  49,  116,  210, 

215 
Dominant  trees,  47,  52,  63,  64,  146, 

15s,   162,  163,  172,  17s,  177, 

183,  192 
Dormant  buds,  iii 
Douglas  fir,  42,  47,  55 

Eastern  balsam,  80 

Entomology,  6 

Epicormic  branches,  135,  176 

Erosion,  41,  56,  77,  103,  216,  249,  285, 

289 
Eucalj^pts,  125 


Evenaged,  25,  33,  45,  59,  83,  98,  104, 

105,  III,  143 
Existence,  struggle  for,  153,  158,  178, 

194 

Farm  woodlot,  103 
Felt,  E.  P.,  268 
Femow,  B.  E.,  i,  177 
Final  crop  trees,  175,  177 
Fir,  Douglas,  42,  47,  55 

white,  274 
Fire,  annual  loss,  241 

causes  of,  260 

character  of,  250 

classification  of  injuries  caused  by, 
243 

crown,  250,  257 

effect  of  slash  upon,  232,  261 

effects  of,  241 

factors  influencing  spread  and  sever- 
ity of,  254 

ground,  250,  256 

hazard  in  selection  forest,  103 

importance  in  forest  protection,  239 

in  relation  to  fungi,  235 

in  relation  to  grazing,  287 

injury  as  compared  with  fungi,  275 

injury  as  compared  with  insects,  263 

insurance,  55 

lines,  198 

methods  of  protection,  259 

patrol,  234 

Peshtigo,  250 

protection,  6,  241 

regions  of  most  severe,  253 

resistance  of  tree  species  to,  244 

seed  trees,  54 

SL[\dcultural  treatment,  effect  of,  in 
protecting  against,  260 

slash  in  relation  to,  217 

surface,  250 

use  of,  to  secure  reproduction,  29 
Fisher,  W.  R.,  239 


346 


INDEX 


Floods,  250,  296,  297 
Forage,  284,  290 

injury  to,  by  fire,  249 
Forest,   CcEur  d'Alene  National,  209 

form  of,  12,  25,  45,  59,  83,  III,  127, 
178 

Minnesota  National,  57 

protection,  237 

State,  of  France,  124 
Forest  Terminology,  i,  299 
Forest  Service,"^^!!.  S.,  54,  96,  208,  209, 

254,  268 
Forests,  production  in  unmanaged,  3 

unmanaged,  12,  141 

virgin,  16,  83,  107 
Form  of  forest,  12,  25,  45,  59,  83,  103, 

III,  127,  178 
France,  139 

State  forests  of,  124 
French  method  of  thinning,  162,  172, 

177,  182,  188 
Frost,  123,  124,  139,  279 
Fumes,  injury  by  acid,  279 
Fungi,  48,  128,  142,  159,  19s,  199,  211, 
274 

action  in  rotting  slash,  277 

climate  favorable  to,  275 

importance  in  forest  protection,  239 

injury  as  compared  with  fire,  275 

injury  as  compared  with  insects,  275 

injury  caused  by,  275 

methods  of  control  and  prevention, 
277 

root  destroying,  277 

silvicultural    measures    as    protec- 
tion against,  277 

slash  in  relation  to,  216,  219,  235, 
278 

wood  destroying,  276,  277 
Furst,  H.,  264 

German    method    of    thinning,    162, 


Germination,  favorable  conditions  for, 

of  seed,  17,  28,  29,  60 
Gipsy  moth,  265,  268,  270 
GirdUng,  30,  151,  152 
Goats,  284,  286 
Grades  of  thinning,  162 
Graves,  H.  S.,  8,  96,  117,  134,  210 
Grazing,  40,  56,  78,  104 
benefits  versus  injuries  from,  287 
effects  of,  285 

on  reproduction,  286 

on  soil,  285 

on  trees  oast  reproduction  stage, 

287 
upon  the  control  and  prevention 
of  fires,  287 
exclude,  to  prevent  avalanches  and 

shifting  sands,  297,  298 
importance  in  forest  protection,  238, 

239 
kinds  of,  animals,  284 
methods  of  control  and  prevention, 

288 
protection    against    domestic    ani- 
mals, 284 
protection  by  close  regulation  of, 

289 
protection  by  exclusion  of  animals, 

289 
regional  importance  of,  in  forests, 

284 
returns  from,  287 
Greeley,  W.  B.,  124 
Ground  fire,  250,  256 
Group  method,  37 
Group  seed  tree  method,  50,  53 
selection  method,  96 
shelterwood    method,   66,    70,    72, 

75 
Groups,  clearcutting  in,  37 
Growing  stock,  unmerchantable,  211 
Growth,  current,  96 
diameter,  105,  157,  171 


INDEX 


347 


Growth,  effect  of  fire  upon,  248 
favorable  conditions  for,   of  seed- 
lings, 17,  40,  49 
height,  106,  157,  200 
mean  annual,  90,  91 
rapid,  122,  136 

Hail,  279 

Hardwoods,  80 

Hartig,  R.,  274 

Height  growth,  106,  157,  200 

Hemlock,  105,  106 

Hess,  R.,  237,  239 

High  forest,  121,  136,  139 

methods,  15 
Hirst,  E.  C,  234 
Hogs,  284,  286 
Hopkins,  A.  D.,  263,  267 
Hopping,  R.,  234,  266 

Improvement  cutting,  142,  143,  144, 

192,  208 
India,  228 

Inferior  species,  3,  42 
Injury  by  fire,  243 

to  forage,  249 

to  human  life,  250 

to  stream  flow  and  industry,  249 

to  the  productive  power  of  the  for- 
est, 248 

to  the  soil,  247 

to   trees   containing   merchantable 
material,  244 

to  young  growth,  246 
Insects,  41,  142,  159,  195,  199,  211 

and  fires,  265 

causes  of  attacks,  265 

character  of  injury  by,  263 

classification  of,  264 

damage  caused  by,  263 

injury  as  compared  with  fungi,  275 

methods  of  control  and  prevention, 
267 


Insects,  most  dangerous  classes  of,  265 
protection  against,  263 
protection  of  natural  enemies  of  in- 
jurious, 267 
silvicultural  measures  as  protection 

against,  270 
slash  in  relation  to,  216,  219,  235, 

268 
Interlucation  cutting,  163,  171 
Intermediate   cuttings,    6,    102,    141, 

153,  192,  208,  210 
appHcation  in  evenaged  versus  un- 

evenaged  stands,  143 
assistance  cuttings,  142 
classification  of,  142 
cleaning,  142,  144 
damage  cutting,  194 
definition,  141 
disengagement  cutting,  142 
improvement  cutting,  142,  144,  192, 

232 
hberation  cutting,  142,  144, 159,  232 
pruning,  143 
release  cutting,  142 
salvage  cutting,  142,  144,  194,  232 
severance  cutting,  143,  232,  261 
slash  disposal  for,  231 
thinning,  142,  144,  232 
weeding,  142 
Intermediate  trees,  134,  156,  162,  163, 

172,  175,  177,  183,  192 
Irregular  strip  method,  37 

Keene,  N.  H.,  80 
Knapp,  F.  B.,  202 
Koch,  Elers,  234 

Landslides,  41,  56,  77,  102,  216,  296, 

297 
Larch,  western,  55 
Liberation  cutting,  142,  143,  149,  159, 

208,  232 
Light  burning,  227 


348 


INDEX 


Loblolly  pine,  58 
Lodgepole  pine,  27,  42,  108,  234 
Logging,  8,  9,  79,  95,  98,  104,  204,  221 
control  of  waste  and  destruction  in, 
211 
Longleaf  pine,  229,  286 
Lopping  of  slash,  225,  230 

Marking,  205,  207 

Marking  rules,  208 

Mason,  D.  T.,  234 

Mattoon,  W.  R.,  114 

Mean  annual  growth,  90,  91 

Method,  artificial  reproduction,  18,  25 
border  cutting,  70 
brush  disposal,  25,  29,  49,  116 
clearcutting,  25  to  43,  207 
coppice.  III  to  126 
coppice  forest,  15,  207 
coppice  with  standards,  127  to  140, 

207 
group,  37,  72,  75,  96 
high  forest,  15 
natural  reproduction,  18,  26 
of  controlling  cuttings,  204 
of  controlling  grazing,  288 
of  controlling  insects,  267 
of  controlling  tree  diseases,  277 
of  fire  protection,  259 
of  slash  disposal,  220  to  229 
polewood  coppice,  117,  207 
reproduction,  5,  11  to  24,  142 
seed  tree,  15,  34,  44  to  58,  207 
selection,  14, 15,  56,  57,  72,  77,  83  to 

no,  137,  207 
shelterwood,  14,  15,  34,  56,  59  to  82, 

108,  139,  207 
sprout.  III 
thinning,  160  to  185 
uniform,  66 

Mice,  protection  against,  294 

Minnesota  National  Forest,  57 

Minnesota  State  Forestry  Board,  234 


Mitchell,  J.  A.,  220 
Munger,  T.  T.,  296 

Natural  pruning,  176,  178 
Natural  reproduction,  15,  17,  19,  36, 
45,  56,  58,  59,  64,  80,  84,  103 

advantages  of,  21,  77 

compared  with  artificial,  18  to  22 

effect  of  fire  upon,  248 

factors  influencing,  17, 18,  28,  29,  97 
Nehasane  Park,  246 
Nisbet,  J.,  172 
Norway  pine,  57,  264 
Norway  spruce,  41 

Oak,  80,  134,  169,  286 

red,  199 

scrub,  147,  256 

white,  138 
Oppressed  trees,  156,  162 
Ordinary  method  of  thinning,  162, 177, 

182,  183 
Oregon  State  Board  of  Forestry,  242 
Overtopped  trees,  134,  156,  172,  175, 
176,  178,  183,  192 

Partial  cuttings,  59 

Patch  method,  37 

Patches,  clearcutting  in,  37 

Pathology,  6 

Patrol,  234 

Pearson,  G.  A.,  48 

Peshtigo  fire,  250 

Peters,  J.  G.,  260 

Piling  and  burning,  29,  221,  229,  232 

Pihng  of  slash,  220,  230,  234 

Pine,  169 

chir,  228 

loblolly,  58 

lodgepole,  27,  42,  108,  234 

longleaf,  229,  286 

Norway,  57,  264 

scrub,  42 


INDEX 


349 


Pine,  shortleaf,  58,  154,  286 

slash,  58 
>    southern,  42 
western  white,  210,  274,  275 
western  white,  type,  55,  209 
western  yellow,  48,  80,  81 
white,  9,  57,  80,  145,  149,  154,  163, 
177, 199, 202, 246,  277, 278, 288 
white,  weevil,  269 
Plummer,  F.  G.,  241,  254 
Polewood  coppice  method,  116,  117, 

139,  207 
Pollard  head,  119 
PoUarding,  119,  297 
Poplar,  yellow,  95 
Populus  deltoides,  49 
Porcupines,  protection  against,  293 
Practice,  of  silviculture,  i,  2 

silvicultural,  2,  12 
Preparatory  cuttings,  60,  63,  68,  76,  80 
Primary  cutting,  71,  74 
Progressive  strip  method,  39 
Protection,  5,  6,  41,  107,  123,  137,  237 
against  animals,  other  than  insects 

and  domestic  animals,  293 
against  avalanches,  296 

domestic  animals,  grazing,  284 
floods,  296,  297 
fungi,  274 
insects,  263 
landslides,  296,  297 
shifting  sands,  296,  298 
sun  and  wind,  30 
tree  diseases,  274 
cost  of,  9 
fire,  6,  239,  241 
necessity  of,  4 
to  the  site,  102,  117 
Pruning,  136,  138,  143,  198 
cost  of,  202 
Knapp's  system,  202 
natural,  176,  178,  198 
Purpose  of  silviculture,  5 


Rabbits,  protection  against,  294 

Rankin,  W.  H.,  274 

Red  oak,  199 

Red  spruce,  80,  184 

Release  cutting,  142 

Removal  cuttings,  60,  64,  68 

Reproduction,  cost  of,  9 

cuttings,  6,  139,  172,  178,  19s,  210, 
229 

method,  5,  11 

methods,  classification  of,  14 

methods,  field  identification  of,  12 

origin,  18 

period,  6,  13,  70,  144,  178 

slash  in  relation  to,  217 

sprout,  119 

standard,  methods,  11,  15,  16,  142 
Reserve  seed  tree  method,  52 
Ribes,  9,  278 
Rodents,  28,  49 
Root  coUar,  iii 
Root-rot,  279 
Root  suckers,  in 

Rotation,  13,  59,  77,  89,  91,  100,  107, 
115,  121,  124,  132,  134 

affected  by  pruning,  198 

lengthened  by  thinnings,  182 

shortened  by  thinnings,   156,   158, 
175 

shortened  to  control  fungi,  278 

Salvage  cutting,  142,  143,  144,  194, 

208 
Sampson,  A.  W.,  285 
Scattered  seed  trees,  53,  57 
Scattered  seed  tree  method,  45 
Schlich,  W.,  169,  237,  239 
Schwappach,  138,  169 
Scrub  oak,  147,  256 
Scrub  pine,  42 
Second  growth,  81 
Secondary  cutting,  71 
Secrest,  E.,  288 


350 


INDEX 


Sectional  area,  i6i,  172 

Seed,  dissemination,  27,  29,  48,  51,  64 

loss  from  rodents,  28,  49 

production,  48 

source  of,  27 

stored  in  the  duff,  27,  42,  224 

stored  on  the  trees,  27,  42 

supply,  17,  45,  57 
Seed  cutting,  60,  63,  68 
Seed  groups,  51 
Seed  tree  method,  15,  34,  44,  59,  77 

advantages,  55 

application  of,  57,  79    • 

definition,  44 

details  of,  45 

disadvantages,  55,  56 

marking  for,  207 

modifications  of,  50 

slash  disposal  for,  230 
Seed  trees,  44,  47,  48,  57 
Seedbed,  61,  63 
Seedling  sprouts,  132 
Selection,  14,  15,  56,  57,  72,  77,  137 

advantages,  102 

apphcation  of,  106,  297,  298 

definition,  83 

details  of,  84 

disadvantages,  102,  104 

extensive  versus  intensive  apphca- 
tion, 98 

increment  under,  104 

marking  for,  207 

modifications  of,  96 

protection  against  frost  and  snow, 
279 

quality  of  timber  produced,  104 

requires   protection   from   grazing, 
289 

single  tree,  87 

slash  disposal  for,  230 

strip,  98 

thinning,  177 
Severance  cutting,  143,  195,  208,  261 


Shallow  rooted  species,  40,  46 

Sheep,  284,  286,  289 

Shelterwood,  14,  15,  34,  56,  57,  59, 108, 

139 

advantages,  77 

apphcation  of,  79,  228 

definition,  59 

details  of,  59 

disadvantages,  77,  78 

extensively  apphed,  72,  80 

groups,  72,  75 

intensive  application  of,  72,  78 

marking  for,  207 

modifications  of,  66 

number  of  cuttings,  60 

protection  against  frost,  279 

slash  disposal  for,  230 
Shifting  sands,  296,  298 
Shortleaf  pme,  58,  154,  286 
Silvics,  I,  2,  15,  18 
Silvicultural  practice,  2,  12,  198 
SUvicultural  system,  11 
Silviculture,  compared  with  agricul- 
ture, 2 

cost  of,  7 

field  of,  5 

intensive,  2,  141,  203 

practice  of,  i,  2 

purpose  of,  5 

relation  to  silvics,  i 
Simple   coppice,   in,   127,   136,   137, 

138 
Single  tree  selection,  87 
Site,  preparation  of,  2,  6,  57,  63,  116 

range  of,  16 
Slash,     apphcation    of     methods    of 
disposal,  229 

broadcast  burning  of,  223,  229 

burning  as  logging  proceeds,  223 

coniferous,  216 

cost  of,  233 

definition,  215 

disposal  affects  insect  control,  268 


INDEX 


351 


Slash,  disposal  of,  25,  29,  49,  116,  210, 

215 

disposal  of,  protects  against  fire,  261 

disposal  of,  to  control  fungi,  278 

hardwood,  216 

light  burning,  227 

lopping  of,  225,  230 

methods  of  disposal,  220 

piUng  and  burning  of,  221,  229,  232, 
234 

piHng  of,  220,  230 

pulling  the  tops,  226 

rotted  by  fungi,  277 

selecting  the  method  of  disposal,  232 

silvicultural  effects  of,  215 
Slash  pine,  58 
Snow,  damage  by,  279 
Snowshdes,  41,  56,  77,  102 
Society  of  American  Foresters,  i,  154 
Soil,  effect  of  grazing  upon,  285 

injury  by  fires,  247 

injury  by  Ught  burning,  227 

slash  in  relation  to,  216,  232 

treatment  of,  26,  30,  50,  57,  63,  116 
Southern  pines,  42 
Spacing,  20,  199 

Special  methods  of  thinning,  183 
Sprout  method,  in 
Sprout  reproduction,  119 
Sprouting  ability,  113,  115 
Spruce,  Norway,  41 

red,  80,  184 
Squirrels,  protection  against,  294 
Stagheadedness,  279,  280 
Standard  crown  classes,  155 
Standard  reproduction  methods,   11, 

IS,  16,  142 
Standards,  127,  132,  134,  138 
Stands,  evenaged,  25,  45,  98,  104,  143, 
178 

life  history  of  evenaged,  1 59 

location  of,  31 

minimum  size  of,  13 


Stands,  natural  development  of,  153 
protection  of,  6 

treatment  of,  during  period  of  re- 
generation, 5,  II 
treatment  of,  during  that  period  of 
rotation  not  included  in  period 
of  regeneration,  6,  26 
two-storied,  45 

unevenaged,  83,  91,  105,  143,  178, 
213 
State  Forests  of  Connecticut,  259 
State  Forests  of  France,  124 
Strips,  clearcutting  in  alternate,  32 
irregular,  37 
progressive,  32,  35 
selection,  98 
shelterwood,  66,  68,  69 
Struggle  for  existence,  153,  158,  178, 

194 
Stumps,  low,  114 
Simscald,  injury  from,  196 
Suppressed  trees,  156,  162,  172,  175, 

177 
Surface  fires,  250 
Sustained  annual  yield,  90 
Switzerland,  106 
System,  silvicultural,  11 

Terminology,  forest,  i,  299 
Thmnmg,  134,  142,  143,  144,  i53>  192 

advantages  of,  156 

amount  removed  in,  163,  175,  182 

appUcation  of,  185 

assists  in  securing  reproduction,  34 

Borggreve's  method  of,   162,   177, 
188 

French  method  of,  162,  172,  188 

German  method  of,  162,  188 

grades  of,  162 

in  plantations,  189 

increases  yield,  157 

interval  between,  186 

keeps  the  stand  healthy,  159 


352 


INDEX 


Thinning,  lengthen  rotation  by  use  of, 
182 
makes  stand  more  resistant,  158 
marking  for,  208 
methods  of  making,  160 
ordinary  method  of,  162,  176 
quahty  improved  by,  157,  182 
shorten  rotation  by  use  of,  156,  175 
special  methods  of,  183 
time  to  start,  159,  176,  183 
to  protect  against  insects,  270 
to   protect   against    tree    diseases, 

277 
yield  from,  163,  170 

Top  lopping,  225,  230 

Torch  for  burning  slash,  222 

Toumey,  J.  W.,  19 

Trametes  pini,  47 

Tree  diseases,  classification  of,  276 
methods  of  control  and  prevention, 

277 
other  than  those  produced  by  fungi, 

279 
protection  against,  274 

Tubeuf,  K.  F.,  276 

Tuhptree,  138 

Two-storied  form,  45,  54 

Underbrush,  disposal  of,  26,  29,  49, 

116 
Understory,  54,  172 
Unevenaged,  83,  91,  103,  105,   108 

143.  213 
Uniform  method,  66 
U.  S.  Forest  Ser\ace,  54,  96,  208,  209, 

254,  268 

Vegetation,  undesirable,  29,  172 
Virgin  forests,  16,  83,  107 
Virgin  timber,  method  of  cutting,  42, 
76,  81,  100 


Wagner,  70 

Wagner's  border  cutting,  70 

Waste  in  logging,  control  of,  211 

Weeding,  142 

Weeds,  removal  of,  49 

Weir,  J.  R.,  276 

Western  larch,  55 

white  pine,  210,  274,  275 

white  pine  tj^e,  55,  209 

yellow  pine,  48,  80,  81 
Weyl,  L.  H.,  285 
White  ash,  138 

fir,  274 

oak,  138 

pine,  9,  57,  80,  145,  149,  154,  163, 
177,  199,  202,  246,  288 
blister  rust,  277,  278 
weevil,  269 
Willow,  basket,  125 
Wimmenauer,  169 

Wind,  danger  of  uprooting  or  break- 
ing by,  35,  46,  57,  78,  92,  137, 
188 

direction  in  relation  to  location  of 
cuttings,  28,  280 

effect  on  fires,  258 

fimgi,  as  cause  of  losses  from,  277 

necessity  of  clearcutting  to  avoid 
loss  from,  40 

protection  against,  68,  103,  158,  196 

value  of  groups  in  resisting,  51 
Wind  River  Experiment  Station,  47 
Woodward,  K.,  288 
Wolf  trees,  142,  150 
Woolsey,  T.  S.,  Jr.,  205 

YeUow  poplar,  95 

Yield,  sustained  annual,  go 

Zon,  R.,  113 
Zoology,  6 


noramr  UBRAnr 

N.  C  State  College 


Wiley  Special  Subject  Catalogues 

For  convenience  a  list  of  the  Wiley  Special  Subject 
Catalogues,  envelope  size,  has  been  printed.  These 
are  arranged  in  groups — each  catalogue  having  a  key 
symbol.  (See  special  Subject  List  Below).  To 
obtain  any  of  these  catalogues,  send  a  postal  using 
the  key  symbols  of  the  Catalogues  desired. 


1 — Agriculture.     Animal  Husbandry.     Dairying.     Industrial 
Canning  and  Preserving. 

2 — Architecture.       Building.       Concrete  and  Masonry. 

3 — Business  Administration  and  Management.     Law. 

Industrial  Processes:   Canning  and  Preserving;     Oil  and  Gas 
Production;   Paint;  Printing;  Sugar  Manufacture;  Textile. 

CHEMISTRY 
4a  General;  Analytical,  Qualitative  and  Quantitative;  Inorganic; 

Organic. 
4b  Electro-  and  Physical;  Food  and  Water;   Industrial;  Medical 

and  Pharmaceutical;  Sugar. 

CIVIL  ENGINEERING 

5a  Unclassified  and  Structural  Engineering. 

5b  Materials  and  Mechanics  of  Construction,  including;  Cement 
and  Concrete;  Excavation  and  Earthwork;  Foundations; 
Masonry. 

'5c   Railroads;  Surveying. 

5d  Dams;  Hydraulic  Engineering;  Pumping  and  Hydraulics;  Irri- 
gation Engineering;  River  and  Harbor  Engineering;  Water 
Supply. 


CIVIL  BNGINKERING— Continued 
5e   Highways;     Municipal     Engineering;     Sanitary     Engineering; 
Water    Supply.      Forestry.      Horticulture,    Botany    and 
Landscape  Gardening. 


6 — Design.  Decoration.  Drawing:  General;  Descriptive 
Geometry;  Kinematics;  Mechanical. 

ELECTRICAL  ENGINEERING— PHYSICS 

7 — General  and  Unclassified;  Batteries;  Central  Station  Practice; 
Distribution  and  Transmission;  Dynamo-Electro  Machinery; 
Electro-Chemistry  and  Metallurgy;  Measuring  Instruments 
and  Miscellaneous  Apparatus. 


8 — Astronomy.      Meteorology.      Explosives.      Marine    and 
Naval  Engineering.     Military.     Miscellaneous  Books. 

MATHEMATICS 
9 — General;    Algebra;   Analytic  and   Plane    Geometry;    Calculus; 
Trigonometry;  Vector  Analysis. 

MECHANICAL  ENGINEERING 
10a  General  and  Unclassified;  Foundry  Practice;  Shop  Practice. 
10b  Gas  Power  and    Internal   Combustion   Engines;   Heating  and 

Ventilation;  Refrigeration. 
10c   Machine  Design  and  Mechanism;  Power  Transmission;  Steam 

Power  and  Power  Plants;  Thermodynamics  and  Heat  Power. 
11 — Mechanics.  

12 — Medicine.  Pharmacy.  Medical  and  Pharmaceutical  Chem- 
istry. Sanitary  Science  and  Engineering.  Bacteriology  and 
Biology. 

MINING  ENGINEERING 

13 — General;  Assaying;  Excavation,  Earthwork,  Tunneling,  Etc.; 
Explosives;  Geology;  Metallurgy;  Mineralogy;  Prospecting; 
Ventilation.  

14 — Food  and  Water.  Sanitation.  Landscape  Gardening. 
Design  and  Decoration.     Housing,  House  Painting. 


I!  ilii 


